So I'm thinking of the GOP field and which candidate scares me the most - right now - as a Dem, and least.
Least Scariest: Giuliani. I would almost love him getting the nomination. With Rudy, it's almost a case of not throwing Br'er Rabbit into the briar patch. A New York city mayor with a hot temper, three marriages (one of them to a cousin), shady business dealings up the wazoo, and a horrible judge of character (Bernard Kerik)? No, Br'er Bear, don't throw me in that thar birar patch! I still don't see how his social positions make it through the GOP process with its fealty to the religious far right, but it's almost worth it to hope that they give him a pass.
Kinda Scary: Romney. Has the good looks and the slick tongue to make a go of it, but already the template is being drawn for a John Kerry style flip-flop caricature. Also has shady business skeletons in his closet, and his one term at governor was essentially a mulligan - so much so that Massachusetts picked a Democratic governor as his sucessor after a string of Republican ones. (Will people start picking up on the fact that his first name is really "Willard"? That's got "Felix" written all over it.)
Scariest: McCain. The base doesn't love him, but still way too many Democrats and independents do. For as wrong as he is and continues to be about Iraq, his Vietnam service seems to get him a pass. Of all the GOP candidates, he's the strongest against a Dem and will require the most resources and work to take down.
Overall, I'm about 62% sure right now (I reserve the right to flip flop on that as time goes by) that the next president will be a Democrat, thanks in large part to Bush/GOP fatigue (Iraq, Katrina) as well as a slight shift towards the Dems in the public consciousness as well as enthusiasm for the Dem field (Clinton, Obama, Edwards and maybe maybe maybe Gore).