Technically, it depends on your personal preference but personally, I wouldn't label any of them as even remotely good. Typical cheap shovelware that would add +1 to your library for each game but you'd most likely never actually play any of them for more than maybe 5-10 minutes if at all. Just my opinion, though. =)

I hear Exist is pretty good, but I havent played it personally. Reviews seem decent on it too

Thank you, added!

I buy the GoGos from GroupBuys, since they're much cheaper this way but I've read comments from people who tried to buy it full price and received a request to verify their identity - maybe it was for the first purchase, I can't say for sure and right now I can't seem to find an example of such a comment.
No extra fees as far as I know. They do have discount coupons from time to time (not at the moment though).

Just to confirm shakti's posting, since I buy there directly: no fees. Also I never had to verify my identity.