Paul Merton is my favourite commedian, its him who makes Have I Got News For You the best commedy pannel show on TV for my money. His travel series to China is also one of my favourite series (was disappointed by the India one though).
Simon Amstell, David Mitchell, Russel Howard, Dara O'brian, Lee Mack, Stephen Fry, Noel Fielding and Reginald D Hunter are also good - I'm sure theres more but those are off the top of my head.
Overrated commedians in my opinion: Lee Evans, Ricky Jervais, Jo Brand and Russel Brand are the ones that spring to mind other people find funny, but not my cup of tea