gotta say ice dragon is my fav....3 litre bottle for £3.50 and it's 7% so will get you completely mashed quite quickly. You can probably get 4 really really quality nights out of 1 bottle
ice dragon and white lightning are such student drinks, cheap and vile...perfect for when you're broke. there's a somerfields round the corner from my halls, they stock loads
we had "the dragonator" challenge on my floor earlier in the year, had to drink the entire bottle in under 6 hours starting at 3pm on a Saturday. As a result of the chaos which resulted 4-5 hours later 10 of us had to see the warden the following evening and were told we'd be thrown out if we ever did it again