Second would have to be Harpoon IPA. First time I had one I had the bartender triple-check that I was actually drinking an IPA. It tasted like an amber lager.
Strange, Harpoon is one of my favorites as far as basic balanced IPAs go. It's one of the rare ones I'll order regularly. Very flavorful without being extreme.
If I had to pick one as the worst I'd say the Rebel grapefruit from Sam Adams.