Well let's see:
Rudy Guiliani - Pros: Already widely known, has the potential to put some blue states with large electoral votes in play, has served in an executive role, well thought of for his leadership during 9-11, could raise money out the wazoo, conservative on fiscal and security issues. Cons: Moderate on social issues, more likely quasi-liberal, which hurts him in a Republican primary.
Bill Frist - Pros: Relatively widely known, true conservative on all issues, is a doctor (has instant credibility with the healthcare issue), has done a good job in the Senate. Cons: Nerdy, not awe-inspiring, thought of as "inside the beltway", not sure he puts any blue states in play.
Mitt Romney - Pros: Looks "presidential", is a sitting governor, has the potential to put some blue states with large electoral votes in play because of geography, good record in business and government, is not an "inside the beltway" figure, proved he could win in probably the most liberal state, conservative on all issues. Cons: Not widely known with most red state general population, Mormon (I don't care, but some do)
George Allen - Pros: Served as Governor and Senator, good speaker, strong conservative. Cons: "Inside the Beltway" figure, not widely known, not much appeal in the blue states
John McCain - Pros: Widely known, War Hero status, plenty of experience in Washington, has the experience of a past presidential run, conservative on fiscal and security issues. Cons: Not really well-liked by most Republicans, moderate on social issues, will be in his 70's by 2008, could be viewed as "Inside the Beltway"
Mark Samford - Pros: Experience as Congressman and Governor, conservative on all issues Cons: Not widely known, comes from a state without many electoral votes, has no chance of picking up any of the blue states
Jeb Bush - Pros: He's a Bush, Governor in a swing state, Florida has many electoral votes, conservative on most every issue, ability to raise money. Cons: He's a Bush, moderate on immigration issues, not sure he could do any better than his brother, strong chance he could do worse.
These are the names I'm hearing most often. I don't mean to slight anyone.
Good analysis. I still have more faith in Sanford, though. With the right running mate he could pick up a blue state or two-in fact he has potential to be another Reagan if he plays his cards right.
What about Tim Pawlenty?
Bill Owens is another name. Colorado Governor.