Happy birthday! GothGirl raises a good point, if it is your first time drinking, take it easy and have some drinks like rum and coke, screwdrivers, or gin and tonic (my personal favorite). If it is your first time drinking, I’d stay away from too many shots…
However, if you are not a stranger to drinking, then I’d put forth the Jager-bomb, irish car bomb, three wise men, and possibly a black and tan (mmmmm….good beer).