I find that when I give a concierge some of my research they can give opinions on them and sort of know my taste and say "yes, that one" or offer better suggestions. A few times I've had the concierge tell me I'd already found the coolest/hippest restaurant. Sometimes they can use their "clout" to get you in if it's popular or new.

When we haven't given any suggestions or criteria about the kind of places we like and just say close to the hotel, I find that a concierge will often give more chain/touristy suggestions and more likely a place they get a kickback from.

For me, the less touristy and more local the better. No offense to the other poster, but who really wants to go to a Cheesycake factory when traveling when there is always good local options to try? Don't be afraid to ask the concierge at a high end property about cheap, casual eats.

It's important to also tell the concierge about your experience. They appreciate the feedback and sometimes will give an even better suggestion for the next night or next visit.