i think it's more to do ith personality and the drink consumed. i only drink beer and low-content alcohol; get tipsy and am a merry drunk. pretty laid back, too. mr kicker, however, likes spirits and is a damaged soul...he turns into an arse x
When I drink I get very silly but I know lots of people who become aggressive and some that get very emotional. It probably is to do with your inner personality coming out.
I think it's partly to do with your mood beforehand but also what you are drinking. I have noticed in myself and in other people that different drinks bring out different reactions. For instance, mr mac always giggles like a big girl if he drinks gin, but my dad gets aggressive if he drinks whisky. It's not just because it's spirits, cos they don't get that way with other spirits. I get quite talkative with wine, smug with whisky, maudlin with bacardi and silly with vodka :)
I think you are your true self when drunk. So if your angry and aggressive then thats probably the type of person you are. Either that or there's something bothering you. Me I am the same whatever I drink, just talk more and have a laugh. Nothing exciting there.
Alcohol is a mood enhancer. So, whatever mood you feel in will be enhanced- for better or worse! However, as you know, different drinks can give you different types of 'drunk', but all just enhance your feelings.