Reginald Hill, and I see you have one at the bottom of the stack there. I adore the Dalziel and Pascoe series. His writing is so elegant and the characters really come to life. His Joe Sixsmith books are also good fun.
Peter Robinson is a fantastic crime novelist. His character, Detective Inspector Alan Banks is a fascinating person. The crimes investigated are dealt with in an interesting manner - the books are full of bits and pieces, observations and side stories. It's just a shame I've read everything of Robinson's in my library, and can't seem to find any more titles in the shops! All of his books are excellent.
I know it's too early to tell yet, but I really enjoyed JK Rowling's crime novel under her pseudonym Robert Galbraith, 'The Cuckoo's Calling'. It had all the things a great crime fiction novel should, and left me really excited for her next one. It's coming out this year, and she's already working on the third, so after those ones I might be able to decide if I add her to my official 'favourites' list.
I don't know if I'd say they were my favourite, but I have real all of Donna Leon, Sparkle Hayter and Shalimi Flint...also working through the Sjowall & Wahloo. They're not brilliant but it's a genre of comfort, I guess...