Drew Brees(1) is the obvious number one choice, but its rare that you'd want to pick a qb in the first round, so it's tough to end up with him. Once the primo backs are gone, I would look at the Johnsons to fill my receiver spot and after that Brees is gone, If you find he slips to you at say 14-15, than he becomes too tough to pass up.
Peyton Manning(2) and Tom Brady(3) are basically 2 a and 2b. In the same way as Brees, I'm not like to end up with them, as they never go after the 4 and 5 wrs, who I prefer. What I mean is, I know I can get a good qb 3 rounds later, while the primo receivers will be gone by then. I'd rather wait and not take either of these guys.
Especially when, Tony Romo(4) is available in the fifth round. Back in February, I wrote that you were better off not taking a top 4 qb and waiting for the second tier.(Rodgers, Culter, Rivers) Since then, Romo has dropped below Rodgers and is on par with Rivers in the minds of fantasy players. I still think Romo is fourth. He was 12th last year despite missing 4 games. He is now one of the most underdrafted players in fantasy.
Aaron Rodgers(5) and Phil Rivers(6) are 5a and 5b. Thing is, Rodgers is getting drafted a lot higher. Taking Rivers in the 4th round is a nice solution if your not big on Romo. San Diego is going to have a big year, Green Bay is going to have a big year. Can't go wrong.
Since the winter, Jay Cutler(7) is on a new team but I don't think he drops off much. Maybe from 5c to a clear 7. He is going in the 7th round. Ridiculous; he is a steal in the 6th. The only problem with waiting for Cutler is that if you wait and miss him, there are no more elite options left. So depending on your situation, It may be wise to grab Romo or Rivers when you can.
Everyone else is a risk. Given the improbable situation, Kurt Warner(8) would be my 8th choice. But I've never seen a draft where he is available and the above qbs are gone. Someone else will take the high risk/reward qb way too soon, and regret it when he is injured. Speaking of injury risk, Donovan McNabb(9) will probably have a very good season. But you should have one of the above seven, you don't need a good backup. Buuut, McNabb or Matt Schaub(10) may be all you have left.
If you ended up with one of those three it would be nice to grab a second qb, either the safe Matt Ryan(11) or double your chances of success with a second risk on Carson Palmer(12) or Ben Roethlisburger(13).
The rest of the bunch isn't worth much, I'd just as soon have David Garrard in the 13th as Eli Manning in the 9th or Matt Cassell in the 8th.
If you got one of the top seven, you don't really need a backup. You can fill in bye weeks and short term injuries off the wavier wire. If you didn't you hopefully got two of that next bunch. No point in bothering with guys like Orton or Flacco, not a good idea to waste a 9th rounder on someone who will never get off your bench.