Hacking Best Performance microSDHC for iTouch2?

[DarthVader3257]

I noticed that my SanDisk 4GB microSDHC (it has a 2 with a unfinished circle around it on the top-right corner of the microSDHC) doesn't perform well and therefore lags in most of the games I have on my iTouch2. Can anyone recommend what the best microSDHC 4GB is best for the iTouch2, and can you please include what symbol is on the top right hand corner of the microSDHC? Thanks!