Sanchez is great, and no doubt ready for the NFL, but Stafford is the most ready in my mind. The kid is absolutely outstanding. I can't get over how impressive this guy is. He doesn't put up huge stats so he doesn't get the love from most average college fans, but the kid can make all the throws and has a good head on his shoulders. He's the ideal size for a QB and is mobile enough to escape the pressure when he needs to. He still has a few things to work on, one of them being able to pick up the blitz and where it's coming from regularly, but that's something that will come with time.
Sanchez is great, but Stafford is special. Best QB I've seen coming out of college since at least Carson Palmer, maybe even further back.
As for the comparison in this thread, I'm not a fan of either. The defenses were poor in this game and Cantwell had the edge of actually having a running game. They outran KSU by 273 yards. That is ridiculous. Hard to lose with a stat like that, and hard to look bad as a QB.