Might as well give my two cents. Really depends which Ben 10, 000 you're talking about. Original Ben 10, 000, Ultimate Ben, Ben 10K? Personally the original continuities Ben 10, 000 will always be my favorite. Although I'm sure they would've followed up with Ben 10K instead. I mostly would want original Ben 10, 000 cause he can show off a TON of new aliens we haven't seen... And while I guess the same can be said with Ben 10K and Ken as a costar, just feels more natural with the original.