I don't really hate any generation's starters the worst, but I guess it's tied between 1st and 5th.
My personal favorite was Gen 3 in terms of starters. While Sceptile wasn't that great, it still had its uses; and Blaziken and Swampert were amazing, both in terms of battling and looks. Gens 2 and 4 are tied after that, with Typhlosion and Empoleon being my favorites out of those sets of starters.
Gen 1 just didn't appeal to me much, even back when I was playing it for the first time. The only starter I've ever liked using was Charizard, and even then it wasn't that great compared to my other Pokémon. Gen 5 was the same, even though I really like Samurott, the other two just don't appeal to me.
That's just my personal opinion on it, anyway. I'm rather picky when it comes to starters.