Dude, those Irish Carbomb things are overhyped. I had 2 and plenty more besides, nothing happened. But I suppose thats because my tolerance is way too high , end up spending close to £50 on alcohol every time I go out. The drink that gives you the worst hangover though, is Jim Beam, man, it's the most vile of whiskeys. But I suppose that could have been cause it was stale. Damn though, never having it again.
I never have hangovers the day after though, it usually just wears off in my sleep. Usually it's one of my mates that has to be trolleyed though