Data (If I couldn't be my main STO RA 5 :p ). Why you ask? Well other than being the smartest and strongest thing in the galaxy, I would be able to download my being into a new body and kill off the old one.
(Do not understand what I'm saying? Data died in the last TNG movie you say....WRONG his orig. body was destroyed correct, but he downloaded his entire memory into B4. While being studied[B4], the "Data Matrix" was unlocked and Data was back again....and became Captain of the U.S.S. Enterprise E ). That info is in "The Path to 2409."
Definitely Tom Paris. We have an affinity for the same things [his favorite breakfast is peanut butter toast and, as a kid, that's all I ate for breakfast for years. lol ], not to mention that the relationship between him and B'Elanna Torres is very similar to the relationship between myself and my girlfriend (I'm Canadian and she's American compared to Tom being Human and B'Elanna being half-Klingon)