Straightforward question. Go!
As far as I'm concerned, it's 4 > 3 > 1 > 2 > 5 all the way. 3 and 4 are all-around very solid, but I'd give 4 a slight edge here. 1 is decent, though mostly carried by Venusaur, and Feraligatr is 2's lone saving grace. As far as gen 5 goes... well, the horse has been dead for a long time. Hopefully Gamefreak gets a clue and makes the gen 6 starters good.