For games, I like the reviews on PocketGamer (it's an app, can't remember if it's free or $1), they offer previews, reviews, videos, tons of gaming goodness, its one of my most used apps (besides the games I actually play). I also read the app reviews on TUAW (The Unofficial Apple Weblog), used to read it online, but now, "they have an app for that", I think it's free. I read their app reviews as well. I also like ILounge.com for app reviews, accesory reviews, etc. That's pretty much all I use, though I like Appsniper and AppShopper to see all the new apps coming out on a specific day.