See Hidden pubs for more southside nightclubs
To get thee into Lillies you want to be glam tastic. The Kitchen is a tad more down to earth but not a lot. That the place where Le Clubbers go. Ri Ra is fairly down to earth and it has a bar floor and a clubbing floor. Then there is Coyote, Fireworks (large queues at the door and the bar), Switch and a few others. And remember, if all else fails there's always the peoples favourite...Whelans. It's the hangout for the leftover indy kids (Eoin).
Recently recommended by my pal Stef is the Trinity Arch on Dame Street (near Trinity College). As well as being a small pub, it has a dance area downstairs and, as Stef says, a very "lively" crowd. All these clubs are in Dublin's centre (downtown).