Never let me down yet: Hobgoblin, Tanglefoot is the best of the Badger set, London Pride.
Spitfire's a good session beer, but lighter than the above, but if you shop at Sainsbury's eir 'Kentish Ale' is relabelled Spitfire, and occasionally cheaper.
I try 'em all though. I'd be better at this if I were stood in a supermarket. Temperature wise most things I have slightly below room temperature, maybe a half hour in the fridge an hour before drinking. Cans of the above brews I have cold, as they tend to work better that way. Bombardier is often four quid for four cans, and nice and light to boot.
Remember that pub Hobgoblin is a percent weaker than home stuff, know your dosage and don't make the same mistake I often do