I've had a fondness for Bayleef for a long time, mostly for its design. Torracat and Dewott both stand out for me as well - both for design again, but Dewott because of some of the moves it can learn as well.
Probably would go with Grovyle as my favorite because of his role in PMD. Also Ivysaur strikes me as another middle evolution that wasn't awkward.
Porygon2. Add an eviolite and it's a special wall. It's also just super cute! I really like how rounded it is. Cute duck.
that's not a starter you pineapple I don't know what it is about Quilladin but I just love that doofy round ball. Probably bounces all over the place too.