I guess it really depends on what you mean by "like Fusion Cash"... There literally are hundreds of sites that will pay you, but not all are of the same ilk...
Fusion Cash is what is known as a GPT or "Get Paid To" site in that it has various offers that a person needs to perform in order to get paid. Other well known GPT sites like FC are (as several have mentioned): InboxDollars & their sister site SendEarnings, MyPoints, SwagBucks, CashCrate, TreasureTrooper, SuperPayMe... I have been a member for all of these sites and have cashed out on most. So in terms of being legit, they are legit in that they will pay you if you follow their rules. However as far as a pure GPT site goes, I haven't found anything quite as good as FC. Also you should remember that often the offers on the sites may be the same as on other sites. So if you can get paid for signing up for a survey site on FC, you can probably find another offer on a diferent GPT site for signing up for the same survey site. The problem is that those other sites only allow a person to sign up once, and to have only one account (usually per household). So if you sign up using the FC offer, you won't be able to sign up again under a different GPT site. That is why once I found FC, I decided not to continue on with many of these other sites.
A second category of site for making money I mentioned above is for survey sites. Usually these are legit inasmuch as they will pay you for completing surveys. However "completing" is the operative term here... Often the surveys you take on these sites will start off with more general questions to determine your demographics and to see whether those match the demographics that the survey is looking for. Unfortunately I don't always fit what type of people that the survey is going after, and so it will kick me out of the survey without me completing it (and hence I don't get credit for that survey). With that being said, different survey sites will do different things to lessen the sting of being screened out. Some sites do a very good job of pre-screening you based on info. that you've given to the survey site so that the site will only provide you with surveys that you are most likely to fit their demographic pool and so will be able to complete the survey. Other sites will give you some trivial amount of compensation for trying a survey but being screened out (FC survey's are an example of this where you get a penny even if you don't complete the survey). Note that this compensation may be in the form of a free entry into some sweepstakes that the site holds, so while it's possible to earn 2nd chance money, it isn't as definite as sites like FC that offer a monetary amount. The sites that I liked are OpinionOutpost, Ipsos, Toluna, MySurvey, InstantCashSweepstakes & their sister site PaidViewPoints, and Pine Cone Research. Out of all of them, I think Pine Cone is probably my favorite since they pay out fairly well and immediately (instead of like most sites where you have to accrue a certain amount before you can request a payment); I even was given a debit card from them in which they deposited my earnings instead of sending me checks (although it sounded like this may have been more of a test rather than a true mode of payment that they offer). The main problem about Pine Cone is that you can only sign up by invitation only, so getting in is a little bit of a chore. Also it is one of the few sites that don't offer referral bonuses, so even if a member was given an invite to send out to get new members, there isn't a great incentive to do so. I also like ICS and PVP as well, more so with PaidViewPoints since that is more of a true survey site (ICS is more for along the lines of getting paid for poll questions that are short and have multiple choice answers) as well as the fact that ICS relies mostly on sweepstakes for their payment instead of actual cash (although you do get cash as well). Probably the best thing about PVP is that every day that will have at least one survey available for you that you will be able to complete. Usually this is just a general demographic-establishing survey that PVP itself puts out, and you get 10-cents for completing. But other times there is an actual survey that pays more than just the 10-cents.
A third category are the paid to read sites where you get paid for reading e-mail advertisements. Again, FC has a paid-to-read function on its site. There used to be more of these type of sites, but are becoming more rare or else are changing their format to be more than just a PTR site. Actually the 2 GPT sister sites that I mentioned above (InboxDollars and SendEarnings) were at first more strictly PTR sites (hence why their names have something to do with e-mail like getting dollars in your inbox or being sent earnings to your e-mail). However they have since changed their format to being a GPT site instead to the point that in order to receive paid e-mails from them, you have to be active on their site (eg complete other offers). DonkeyMails is the only one that I know of that is still mostly a PTR, although I think they are more like the last category than a true PTR...
Finally there are Paid To Click (or PTC) sites that will pay you to click on advertisements which send you to the advertiser's website. Usually you need to spend a certain amount of time on the advertiser's site in order to be credited (the amount of time usually ranges from a few seconds to a couple of minutes) and will tend to pay accordingly (so that a "mini" advertisement may require you to visit the site for 5 seconds for 1/10 of a cent, a "regular" ad is 30 seconds for 1 cent, and a "long" ad is 2 minutes for 5 cents). The range of times and earnings varies from site to site, and may also depend on your membership level (eg your free membership may only earn you half of a cent for a "regular" ad whereas a golden member gets 1 cents and a diamond member gets 5 cents for the same ad, however each membership level costs more money up front). These are probably the most plentiful in terms of number of sites (there are even sites that provide people with a framework to create their own PTC site, which is why these have become so numerous). Unfortunately quantity doesn't mean quality. Some sites will be open for a few months but then will shut-down due to a mismanagement of funds. My recommendation is to just get the free memberships and your own referrals, and only use your earnings to upgrade your membership level or to purchase / rent referrals. For these sites, usually age is your friend in that the older sites are ones that know what they're doing and so are less likely to shutdown unexpectedly (the major exception to this was when PTCBox / MatrixMails went under last year, I believe. The parent company MatrixMails had been a long-standing PTR site from I believe 2002 that expanded into the PTC arena with PTCBox. But then in a little under a year, PTCBox went belly-up and a few people actually lost money thinking that because MatrixMails was stable for so long, that it's PTC site would work well too). The PTC sites that I'd recommend are ClixSense, NeoBux, ProBux, and WordLinx. ClixSense is probably the best for novices in that their "regular" ads are worth 1 cent (more sites are decreasing the amount to half-cent or a tenth-of-a-cent, following in NeoBux's footsteps), they offer a guaranteed number of regular ads (1 for free members / 4 for upgraded members), very low upgrade cost ($17 for a year vs. $90 for NeoBux), and if you upgrade you receive commissions for 8-tiers of referrals (so your own referrals are tier 1, anybody they refer are tier 2, anybody that your tier 2 referrals get to join would be your tier 3, etc. all the way down to tier 8; most other sites only offer 1 tier namely your direct or rented referrals).
And you may run across some other sites that claim you can earn money online easily that don't fit in the above categories, namely High Yield Investment Programs (HYIP) and matrix programs. Both of these type of sites are almost definite ponzi schemes. These programs require you to "invest" a certain amount of money before being able to withdraw any of your returns. However there is no guarantee that you will be able to withdraw anything before the site closes let alone that you will make money from those sites.
I'd recommend first going with a good GPT site like FC, maybe check out some of the others as well... From there you can usually find offers to join a survey site, so you can make a few cents just by signing up for another free site where you can earn money. However once you get away from GPT and survey sites, be much more cautious. Many of the PTC sites are little more than a glorified ponzi scheme in that the site makes money by having its members spend money, which is why they tend to have all sorts of calculators showing how if you were a golden member that had 1000 rented referrals who each clicked on 4 ads per day, then you could make over $100 per day (without mentioning that the golden membership and rented referrals all cost you money, and not all referrals will click those 4 ads (and are more likely to average less than 1 ad per day)).
As for any of these sites, don't expect to make a lot of money. Think of it more as a way to make extra pocket change. If you are good at getting referrals, then maybe try going into PTC programs and affiliate marketing, the latter being one of the few areas that you can actually make a decent living on, but requires more work than most are willing to put in.