My favorite restaurants in Temecula are actually Rosa’s Cantina (mexican)in old town and Pat and Oscar’s on the Pond (mostly Italian)on the corner of Rancho Cal and Ynez. , but neither of these are 5 star or high end, they are just good food, casual atmosphere, and my fav is Rosas.
That being said, Baily’s in oldtown would be exactly what you are looking for. look here http://www.oldtowndining.com/ Make sure you eat on the second floor, which is the high end place, not the bottom, which is a nice casual cafe/bar. Ask for a window seat, if you can get one, you will have a nice view of front street, and as an added bonus…. If you go to Costco in Temecula, you can buy $100 worth of dining gift cards to Baily’s for just $79. But, if price really is no object, skip that part.