I don't mean they are necessarily Skrulls. I am thinking about characters like the Vision and Annhilus. IIRC, the current Vision or one that was current was really the Vision's programming downloaded into Iron Lad's armor. The true Vision was destroyed in Disassembled beyond repair.

Annhilus was at some point killed, but created a copy with genetic memory. So while the first Annhilus remains dead he can in a sense stay alive through genetic memory, but technically it is a separate, new being.

Wasn't Tony Stark also one time killed and the current one is actually some alternate, younger version of him that had the original Tony's memories "merged" with him and aged to the proper age?

I think Kang also falls into this category since he has been killed several times, but due to all of his time traveling a new one is always ready to pop up.

Any others?