I had GameFly. 3 of the games were lost in the mail either when being shipped to me or being sent back. THe good thing, as stated above, is that you can report it easily. Te service was too expensive for how long it took items to get to me. I live in Kansas and had to wait on average of 7 days to get anything. It was nice to rent DS games, but I cancelled and am now on GameznFlix.
Now about GameznFlix:
The good:
You can have 3 at a time for $10 less than GameFly's 2 at a time.
They rent 360, PSX, GC, PS2, Xbox, DVD, UMD, HDDVD, and Bluray.
Items get to me sometimes the next day, sometimes within 3-5 days.
The bad:
First game didn't get to me. I had to wait 12 days before they considered it lost. Customer support is really bad.
They don't rent Nintendo DS!!!!
Though 360 selection is great, they appear to have VERY few in inventory. For example, ever since it came out, Dead Rising has been listed as "short wait". Gamefly would only have short wait status for a day or two, then the game would be ready to go.
I hope this helps.