I have all three games here.
Diamond, my Starter was Turtwig and I first caught a Bidoof, Starly, Kricketot, than Shinx. Turtwig and Shinx stuck around till their full evolutions and helped me beat the Elite Four.
Pearl, wanted to try something a bit different cause I was reading up so I started with Piplup (Might do that again) and my first catch was a Shinx. I actually went for a Nature that boosted it's best stat. Now I've got a Turtwig on that game too and went breeding a Female Luxray with a Male Floatzel for Ice Fang. ^_^
Platinum, I went for Starly and put the others into a box and slowly built the team up. I though did start with Chimchar cause while I love Fire-types, couldn't really get past the whole Monkey with the flaming rear thing till now. Both Pokemon are now my top performers and capable of doing ALOT of Damage in short order.