I had kind of a hard time deciding, but I think Kendra. The first slayer was more primal, but I think by the time Kendra came around the slayers had evolved, they weren't just primal, they were smart and well trained. I think the first slayer would just attack but Kendra would take into acount strategy and technique.

Lol, the more I think about this the more it seems like the cavemen or astronauts arguement from Angel. Would the primal slayer (cavemen) win or the more informed modern slayer (astronauts)

kendra has inherited all the skills of her predecessors. So also of the first slayer. So that's why she will win

i think that the first slayer has alot more passion in her fighting cuz that is all she has (kinda like kendra and faith, they dont have the distractions in their life like buffy: friends, family, school, etc) but i think kendra has the skills of her predecessors, intelligence and techinque but im not saying the first slayer doesnt have that either but we dont know much about the first slayer...so i say its an open book on who could win or lose...maybe the fight could last hours lol...

Well Buffy & Kendra were pretty evenly matched, and Buffy & The First Slayer were pretty evenly matched, so I just went with Kendra.