I don't replay them back to back, but I'll look at what the starters become. If I know I want another pokemon in my team at some point, that might factor into my starter choice (fuck now I'm hungry).
I do look up the pokemon I catch and the base stats, type and aesthetics of their evolutions is a big determinant in whether I'll choose to level them up or not. Eventually I look at stats too much and it ruins the mystery and kills any excitement so I quit the game. Good life lesson there.
My Pokemon Crystal Poliwhirl was a fucking beast though. Didn't evolve it because two strengths means two weaknesses and combat is all about hiding your weakest links! Ossu!