Assuming they'd carry over whatever skills/ abilities they had on their shows?
Buffy - can slay almost anything, super strong, great protective instincts; good for some quips; just have to manage her leadership style Willow - could do protection spells, locator spells, good for attacking the undead as well, would know a lot about plants, fun to have around as long as you keep her from going too dark. Dr. Doug Ross - medical know-how, eye candy, good with kids Raylan Givens - take that hat off, Carl. We now have a killer marksman who wears a Stetson like no one's business; used to living pretty simple Alton Brown - good problem solving skills, creative in the kitchen; good conversationalist.