I've got the A-Data 4GB and have had not a single problem with it from day one. I've had it for 3 or 4 weeks now. Plus, I got it for just $30 after MIR. Newegg still has it for that price right now
Newegg.com - A-DATA 4GB MicroSDHC Class 6 Flash Card Model Turbo microSD HC 4G - Retail

__________________
The more complex the mind, the greater the need for the simplicity of play.