VERY familiar to Black Books.
I just finished series 1 and although I liked it a lot, I can't stop thinking about the similarities to Black Books.
I mean think about it. The main characters of both shows comprise of 1) A loud Irishman, 2) A lovable idiot and 3) A love-starved woman. The humour is similar too. A cynic would even call it a rip-off. Even the layout of their office is kinda familiar to the bookstore!
I like both shows, but it's kinda unfair to Black Books since it's 6 years older and only half as popular (judging by the votes here).