My experience with 'house blend' cigars is that they vary. Some suck, some are phenomenal. badwhale just did a review of a house blend called Cerberus, and he liked it (I think). logan37 lives near (or at least used to) a shop that sold these crazy Phoenix cigars that I really liked as well. A local B&M I frequent has 3 house blends, but I'd only ever smoke one of them again. I agree with Winston's assertion to smoke one first. It would suck getting stuck with a box of shitty smokes.

With any and everything else, you're going to have to smoke it to decide if you like it.