Sooo, I did my homework (aka was bored at work) and did some research on London hostels, prices etc. So here we go

btw, all of the below have a bar

)
The Generator - we all know that one
Privates (no matter if 3, 4 or 6-person rooms) are available at GBP 30,50 per person per night. No further description needed
Clink 78 (King's Cross)
Twins available at approx. 41,- , 4-6 bed dorms at 34,- and 8-bed dorms at 31,- per person and night
Clink Hostel • Clink Hostel is located near Kingβs Cross in London
St Christoper's Village (Southwalk)
Twins available at 37, 4-bed dorms 30,-, 6-bed 28,- and 10-bed 26
Hostels in London Bridge - St Christopher's London Hostels
Apparently this one, together with the Generator, is one of THE party hostels

St Christopher's has a few other hostels in London, also one in Camden, but they are all a bit smaller.
How many are we so far?
Well, let me know what you guys think. P!SP!