I agree, Hook Champ is an amazing game! I never get bored of that one. I was thinking about getting Starball, but it just looks too plain. Maybe the gameplay makes up for it though.
Labyrinth Aussie Rules Air Hockey Ramp Champ MiniGore BackBreaker TowerBloxx Paper Toss and more recently iShuffle
There is this new challenging clockwork mechanic type match 3 game called Swapper. It has brilliant graphics and great for pick up and play. Here is the thread for it with video: http://forums.toucharcade.com/showthread.php?threadid=39056
Hook Champ Update with new character and outfits should be out any day, followed by a larger update with new levels and possibly a new game mode (endless/survival). Needless to say, I am excited.
Maybe some of you will disagree with this, but I would actually put NFS Shift and Rockband for best 5-10 minute games (as well as good long session games). They are made to be very mobile. I know they aren't intended to be pickup and play titles. I find that I am not playing really really short bursts anymore but when I know I have less than 2 minutes I'll pull up Cluck it or Flight Control. Very rarely I'll play Orbital when I have only one hand. Rockband's Vocal option also makes up for a good 1 handed game. I still got iDracula on my phone for those rare moments when my brain's basically dead. Thinking about the Chop Chop Ninja game right now to replace my Frogger-chicken times...
I can see why you would say NFSS and Rock Band. Since one race or one song can only take a few minutes, they can be good to play in short spurts. I would definitely recommend Chop Chop Ninja. It is a great beat em' up platformer.