You won't immediately realise the enormity of this bar/club/restaurant when you walk in the front door. That is if you get in - this club is notorious for turning away groups of guys late in the evening, in an effort to keep the male female ratio at roughly 50:50.
Assuming you make it to the first bar, you'll be charged (rather steeply) for your drinks. The first disco is on the same floor, but is a small pokey affair, but plays a good mix of 90's and 00's music. The main disco is underground, and is much larger - it plays an excellent mix of modern dance / house music, if that's your kind of thing.
There are further bars on the floor above the entrance, and a large restaurant with a side entrance - note, if you dine there you can go staight into the club without paying the cover charge, though the food is nothing special.
The club attracts a lot of tourists, due mainly to being located between Picadilly Circus and Leicester Square, and because of its size can be a bit impersonal. Having said that, it's a club I always seem to be drawn back to, mostly because it's a cool place to hang out.
Have a look at its pictures on www.tigertiger-london.co.uk.