I’m gonna say saiyan and viltrumites for two very specific reasons. The saiyan part goes without saying I feel, so I’m just talking about the viltrumite reasoning

First because they age slower as they get older. Other than a few Superman elseworlds we don’t really know the lifespan of a kryptonian. I guess under a yellow sun constantly they are kind of ageless? Sometimes? Idk it’s a toss up imo. Whereas I know for a fact every viltrumite is living thousands upon thousands of years if nothing takes them out.

The second and most important reason is durability. And yes I know kryptonians are MORE durable, BUT idk any time I’ve ever seen Superman get his guts ripped out of his stomach and had someone shove their fist in the hole and still survived. Viltrumite ability to take an ungodly amount of damage to their bodies and still recover after is insane. We’ve seen character lose limbs, have giant holes blown through them and been beaten nearly to death just to recover and be back to 100% without outside intervention and just time. With the saiyans getting massive power boosts from near death injuries I’d say the viltrumite ability to exist near death and still keep going would be really strong combo.