Which micro sd cards are the best?

I am waiting for my kingston 4gb(class 4).Is sandisk any good or how about A-Data.Ive also seen filemate.Also do different classes affect gameplay?

Sandisk are good, I wouldn't recommend using anything other than Sandisk or Kingston, as some games can have issues with other brands.

I use SanDisk for a lot of my storage stuff, and have no issues with them. I don't recall ever using Kingston before, but I've heard their stuff was pretty good also.

Yes Kingston is really good as well as Sandisk, Hyundai and Toshiba are okay too.