Here some of my personal recommendations as I've purchased and played these games:

Sally Spa:
Nice and stressful to get Expert level score

Sally Saloon:
Same as above, LOL

Jojo's Fashion Show 2:
Loved it when it was on PC, even better on mobile gadget like iPhone. Highly recommended. Learn a thing or two about fashion.

Airport Mania:
Don't be fooled by the cartoon-ish airplanes. It's a true-blue time management strategy game and can really stress you out when many planes are trying to land at one time.

A+ Burger:
Not bad but quite stressful as you need to make big numbers of combo in order to pass one level to another.

Build-a-Lot:
A real gem. A fusion of Sim City and business strategy game. Sometimes requires patience as each home is being built.

Flight Control:
No need to describe. One of the best games ever in iTunes store. Many people already talked about it.

Fastlane Racing:
One of the better racing apps out there. Purchased it when price dropped to $0.99 and play it occasionally. This is also the apps I would launch when showing off my iPhone to my friends. Hehe.

Touchsports Tennis 09:
Ain't that many tennis games in iTunes to begin with. This one is pretty good. Caution! It requires full touch-and-tilt movement so your hand might get sore after a while.

Fieldrunners:
Lots of tower defense apps out there but Fieldrunners is the best. That not only coming from me but from slidetoplay, toucharcade, etc, as well. Bought it at $0.99 but it has been priced at $2.99 ever since.

Stone Loops of Jurrasica:
Have been playing this Zuma-like game countless times. Even when I've finished all the levels, I'll go back and restart to begin again.

Price is Right:
Bought it due to $0.99 price drop. A classic if you used to watch the original game show on TV. But too US-centric, hence hard for us to guess the prices. Imagine if the showcase is for Honda City 1.5E or Toyota Vios 1.5G, then very easy to guess the price, right?

This post has been edited by my44: Aug 15 2009, 11:33 AM

Most games like that actually. Personally, I noticed Build-a-Lot also drains a lot, I imagine because of the processing required throughout the game.

Yeah, I've downloaded the trial version and it was somewhat better than Gameloft's Real Soccer 2009. I'm waiting for a price drop before I splurge