In no order :
1) Chikorita line : As the OP said, the most underwhelming starter of the century , both story mode-wise and competitive-wise. Leaf Guard is a horrible ability as set-up is required for it and Meganium still has only decent defenses (100 isn't too good). While it does have good attacking moves like SB, PB etc it can't make use of them with it's bad attacking stats and Grass is just an overall weak type. (5 weaknesses? Come on :/)
2) Feraligatr line : 'Feraligatr - B1g @$$ Pokemon' - Bulbapedia (L0l). Decent at best and worst in appearance, second only to the Unova fire starter. It does have good bulk and a decent attacking stat but that ain't much and it is weighed down by it's speed. The best water-type move it gets is Aqua tail and Aqua Jet. It also learns DD to take care of faster mons and it is an overall decent but simple Pokemon. The biggest downside factor is it's appearance .
3) The fire Unova starter - I don't know it's name and I don't care to know. HORRIBLE :/. Great HP for bulk but can't last long with it's frail defenses and good offenses but horrible speed so it'll most likely be OHKO'd. Also, just like the 'B1g @$$' pokemon above, it has a terrible appearance ;p.
4) Delphox - I like all the other remaining starters except this one and the one below. I don't really know much about it ;p. It has so much wasted potential though.
5) Chesnaught - Same as above.