It really does depend on your music tastes but if you'll enjoy most stuff like me then I'd sample nights at a few different clubs whilst your on your first hol. I'd recomend a trip to Eden (Wonderland or Judgment Sunday), Pacha (most nights are great), Space (I like Carl Cox but I hear there are lots of other good nights, for you I'd prob avoid La Troya unless your three gay guys or if thats your cup of tea) and Amnesia (Cocoon, Cream, Manumission) for a first trip, you get to see San An, Ibiza town and Playa den Bossa and all those clubs offer something each a bit different. Make sure you sample the bars in Ibiza town as well as San An, where I persume your staying?? as for three young lads you'll prob find yourselves in the west end area a lot so make sure you have a good look around as Ibiza has so much to offer. Enjoy!