Looking for recs for a solo diner. I have a few days in Vegas for a conference, staying at the Aria. Any price range is acceptable. I'd like to avoid having to make reservations. Thanks
You are actually in luck - not only are the Las Vegas strip restaurants extremely friendly for solo diners, but in these slow times reservations are not mandatory at all. You have a plethora of good options right at City Center, which gives you a chance to do a "menu crawl" checking out the specials boards at the various places each night before making a choice. Sage has quickly become a personal favorite, and there is some comfortable seating in the bar area for a solo patron. Staying at the Aria also puts you close to a lot of other options, so perhaps you could share some preferences to help narrow it down.
Do Robuchon. They like reservations, but you can usually score a table at a day's notice. It fits your criteria and will undoubtedly impress.
I went to Otto when it was Enoteca San Marco and liked it quite a bit, as well.
If you can get off the strip - go to Raku.
Enoteca San Marco
3355 Las Vegas Blvd S, Las Vegas, NV 89109