May sound cheap, but I just bought one of the first 2 results of a
32GB microSD Card you get from searching from Amazon by SanDisk because of time purposes and because of their ridiculous cheap price range, and to my advantage, the card has worked like a charm, it has been able to record, playback, run apps, and all sorts of reading/writing functions perfectly at my liking, and its a
class 4. I've had this microSD for about 2 months now and filled up around 10 Gigs of it and it still reads/writes at great speeds. I would really recommend it because of it's cheap price, hasn't failed me yet. If you just run random game apps from here and then, listen to heavy amounts of music, and record HD videos from here and there I'd recommend you buy it. Here's the one I bought:
Amazon.com: SanDisk microSDHC 32GB Flash Memory Card (Card Only) SDSDQM-032G-B35,Black: Electronics