Here's my list using yahoo's standard league (10 teams) and scoring. Where I'd start thinking about picking them in parenthesis. Obviously things change as you draft but it's a guesstimate.
1.) Peyton Manning - Never misses a game and is a guaranteed 4000+ yards and 26+ TDs. He might not finish #1 but he's the only QB in the league that you're certain will be in the running. (early - mid 2nd round)
2.) Drew Brees - Will probably be the #1 QB taken in most drafts and be long gone before I consider taking him (mid 2nd round).
3.) Tom Brady - The weapons around him and visions of 2007 will probably be enough to get someone to take him really early. I'm not taking that risk unless he falls a bit. (late 2nd, early 3rd).
4.) Philip Rivers - Great year for a young QB that's been improving (4th round).
5.) Kurt Warner - Only thing from keeping him from being higher is his age and Boldin's status. How many more seasons can a 38 year old throw for 3500+ yards and 25+ TDs? At some point in the 4th round I might find out. (late 4th rounder).
6.) Tony Romo - Say what you want about the choker but it's the regular season that matters in fantasy. There he's been a consistant producer since he took over the starting job 6 games into the 2006 season. (6th round)
7.) Aaron Rodgers - The Packers were horrible but Rodgers fantasy numbers weren't. He has the weapons to do it again. (6th round)
8.) Donovan McNabb - He'd be a lot higher if I knew he'd be healthy or his coach wouldn't do something stupid like bench him. (6th round)
9.) Matt Ryan - Good talent around him that got even better with the addition of Tony Gonzalez. With Turner having a heavy work load last year I think the offense will ask Ryan to do a little more now that he has more experience. (8th round)
If I haven't take a QB by now I generally wait awhile as everyone else already has their starting QB and there isn't a big difference in talent between by #10 guy and the next 3 or 4 guys on my list.
10.) Jay Cutler - Can't stand the guy but he does put up numbers. His WRs are questionable but with a nice young TE and a RB that makes plays in the passing game I'll take my chances (10th round)
Obviously I'm not touching a QB in the first round but after my top 10 RBs and handful of WRs are off the board I'll start considering a QB. If I don't get one of my top 8 generally I'm waiting awhile to pick one and usually going back to back since I'll need a solid back up. I'll solidify my other starters and get a key back up RB before reaching for a guy like Ryan or Cutler. If I miss out on them there's always Matt Schaub, Eli Manning, Ben Roethlisberger or Chad Pennington. Hopefully I'll grab two of them before others start snatching up the back up QBs.