Galcon Fusion, currently on sale, alot of fun, and it involves ships, space, global domination, it's alot of fun and with I think 8 different game modes will be played for a fair while
I found something called 'Free App A Day' aka FAAD. It basically does what it says, it lists 5 free apps each day, including ones that are only going free for that day only.
I'm really liking 'Stick Golf' (one of the those FAAD games a couple of weeks ago, although I think it's only normally 59p).
you can for the iPhone/iPod download an app for freeappaday.com, I sign up to there e-mail list and get the same, another useful site if you are into RSS reading is appshopper.com to easily watch price changes and new apps arriving (it's not just ALL apps unless you want it, but popular new apps, but you can pick whatever RSS feed you want). It's where I saw Master of Alchemy (another good iPad app) had dropped in price so grabbed it.