You could take a look at Frozen Bubble, it's pretty much a clone of Bubble Bobble.
Not sure how good the iPhone/iPod version is but I used to have it on an old Sony Ericsson and it was great.
I recommand Bubble Bash by Gameloft.
Hi,
My wife loved Bust a move or bubble or whatever it was called.
The closest I have come to gameplay is a game called StoneLoops.
Not sure if it counts for much but my wife is now addicted to that too
PD