I'm in the same boat as Colsie below, this was an old haunt of mine many years ago. It was such a great place to hangout and play pool with really diverse types of people. The old Century Tavern was predominantly a Goth/Punk/Pre-Emo crowd with the odd visiting American sailor thrown in just to argue the merits of a 'call shot' game.
Enough nostalgia lets talk about the new Bar Century - well it's pretty much the same as the old one just without the jukebox and pool table. Slightly better sofa section and the beer selection has been improved but at the same rock-bottom (for the city) price.
The second level is gone but it wasn't very popular in the first place, especially when the did the refurb' which tried to make it a sleek bar and totally killed the ambiance.
This is easily one of the best hangout bars in Sydney. The large windows give the lucky ones a clear view of the George and Liverpool Street intersection which is always delivers lively action. Drop in if you've never been there it just might suit you.
The Century Tavern was an old haunt of mine well before World Square was erected across the road. It closed some years ago but has thankfully re-opened, as Bar Century, and to be honest not much has changed. Looks like there's been a new coat of paint but the layout is exactly the same and toilets look they haven't been cleaned properly since the late 90's. There's only one level now as all the upper levels have become a backpacker joint. This means two things - a lot of backpackers in the Century and really cheap drinks at the Century. Was packed on the Friday when I visited with seats by the window prime real estate, as soon as some leaves there's someone waiting to pounce. If you're there long enough you'll get a spot.