agree that it's a matter of taste ... and mine tends to vary from one day to the next ... among my favorites are single malt scotch, port, cognac, red wines (reds are ALWAYS best at room temp*), a full bodied ale ... but a diet Pepsi or an iced tea are pretty common choices for me too ...
* the best means of achieving optimum 'room temp' is to chill the red wine in the fridge (or, in Arkansas, the icebox), then remove the cork (or, in Arkansas, unscrew the cap) and allow it to sit for about 2 hours ...