The alcohol with the most congeners (i.e. the ones that will cause you the worst hangover) from lowest to highest are:
4. Dark rum
2. Red wine
Sorry to crush all your Brandy hopes and dreams. Bourbon also has eight times the congeners of gin and thirty times the congeners of vodka -- so really, it might be time to stop hating on G&Ts.
The video also addresses whether or not you'll get an easier hangover if you drink more expensive alcohols. The answer is that if a liquor is filtered and distilled more, there will be less impurities, and it'll cost more to produce -- so it can mean that if you spend more, you'll save yourself the worse hangover. But... it also means that cheaper vodka and gin could be as bad as expensive bourbon.