Tiamath 4270-1408-1357 (Dusclops, Lampent, Pumpkaboo) No.21117960 Report Chespin is one of my favourite starters, perhaps my most favourite even -and I've been sticking to fire starters almost every gen-.
Chespin in super adorabs and can turn all those leaf-like appendages into spikes.
Quilladin may look bad on first sight, but it's actually quite cute as well in it's own goofy way (pic related). The in game model and the name make it all the better.
Chesnaught is as awesome as a grass starter can get, just look at him, a real bro. Also, it loses the bucktooth and gets fangs and actually has an animation for his spiky shield where his spiky arm-plates form a shield.
I'm not necessarily trying to convience OP, but these are some of the many reasons why I like this starter. I named mine Lancelot.