2 x Lexar 32 GB (633x class 10), 1 x Lexar 16 GB (stock with Inspire) and 1 x SanDisk 32 GB (class 10).
They are all good. I have had one Sandisk MicroSD crap out on me, and no Lexar's, thus the vote for Lexar (plus they are cheaper)
Been using SanDisk from the beginning and have had no issues. I do feel like I should buy stock in it though since I buy so many. I usually buy three or four 32 gig cards at a time and I give whatever I used to the client after I upload it to my laptop. They are usually pretty happy to leave with footage. Price is included in my quote.