I've been with Inbox Dollars and their sister site Send Earnings for a few years, but as others have mentioned, it takes longer to cashout (if you are only doing free offers, like e-mail and videos). I'm not sure if others have noticed this, but it seems like this year I have been getting very few e-mails from them... I'm only getting an e-mail at the end of the week whereas in the past I was getting a few every week. I'm not sure if they're getting filtered out (I don't see them in my spam folder, tho), or if it's a change in their site...
Other good e-mail sites (as Maxinmotion mentioned) is Hits4Pay and their sister site DealsNCash. Hits4Pay is a little better in that I tend to get paid more per e-mail (minimum of 2-cents per e-mail whereas DealsNCash has a min. of 1-cent). MatrixMails is also a very good site as a combo e-mail and PTC site.
For all of the sites, FC is the easiest to cashout. However unlike FC, the others don't have a time-limit to cashout (just have to remain active), which is good, since otherwise I don't think I'd cashout in time and I'd prob'ly just drop out of those sites. Even though it takes longer to cashout, they are all fairly easy to do; I can spend a total of an hour each day going thru all of my e-mail and PTC sites. And even tho I may not get paid by each of these sites every month, out of all the sites I'm involved in, each month I'm getting paid from one site or another. It's this "multiple streams of income" philosophy when it comes to making money on-line. Even though the amount of money and rate of cashouts is low for any one site, by being involved with several good sites can begin to add up. If you're going to be on-line everyday, you may as well try getting involved with several sites and get paid while you're on-line.