I love Snivy!
Oshawott is a pretty neat design.
I like Snivy because it's a reptile, its cute, and I like its upturned nose. C:
Its body shape is also very cute to me. And I always like to choose the starter closest to being reptilian.
Tepig is... Kinda gross to me, until it's an Emboar, then it looks the best of the trio, in my humble opinion.

Snivy's definitely the best, although the best fully-evolved starter is Emboar. Oshawott is cute, and has the best evolved form - Dewott - but the only reason I don't use it a lot is because I don't like Samurott. Shame.

I like all of them, really. I restarted White version a couple of times to test out the other two starters (Snivy and Oshawott) since I picked the Bacon in Black Version and was, no time soon, restarting Black. Not with all that year's worth of breeding and Cobalion being annoying. Anyway, I really like all three of them, if given a chance. I like Oshawott and Tepig a little more than Snivy, Egg move wise. They have a bit of a variety whereas Snivy's aren't so great.

Oshawott with Night Slash|Air Slash|Brine is a good set-up and if it's a Samurott, it can basically cover most weaknesses.

Tepig, that little sucker with Curse + Superpower is deadly, I've tested. Probably the best set-up there. Too bad Tepig doesn't learn a self-healing move. ): Anyway, that's my take on that.

Snivy is awesome, it's looks and all but except for movepool....

Oshawott's design is coolest out of the three.... I love the stats and also the moves that it learns

Tepig, the only reason I like this pokemon is because of its shiny tribute it's awesome when it's blue