Kanto starters=all equal awesome. No complaints.
Johto starters=all are cute. Chikorita is CUTE! How can anyone hate it? Meganium can learn OUTRAGE from the move tutor in Platinum. It can also learn Ancient Power, Seed Bomb, Synthesis, Leaf Storm, Energy Ball, Iron Tail. It's a great Pokemon if you know how to use it properly. However, I'm not too fond of Croconaw, but it has grown on me.
Hoenn starters=Torchic looks like a chicken. Never really expected a chicken to blow flames out of its mouth. It really is a "Fried Chicken." Lol I didn't really like it in RSE, but it's cuter in Dppt. They're all cuter in Dppt than in their game.
Sinnoh starters=I like them all, but my least favorite is Turtwig. Its evos are cool, but Turtwig is meh...I just like the other grass starters better.
I don't hate any. If anything, the one I like least is Pikachu. Sure, it was super cute in Yellow version, but it hasn't been as cute in recent games. Though, Platinum's sprite of Pikachu is better than the one for D/P.
Don't forget that Pikachu and Eevee are also starters! XD