I've hesitated to post of our recent dining experiences in Riverside, but having asked for advice here, I feel obliged.
We had a wedding to attend in Riverside and stayed at the historic Mission Inn for the weekend as it coincided with our anniversary.
Stopped at In N Out on the way there. Fries ordered well done are a revelation. It was one of our better meals.
Dinner was at Duane's Steakhouse at the Mission Inn. Service is old school (my husband was asked what the lady would enjoy this evening), and perfectly pleasant. Steaks were fine. Vegetarian risotto starter was a highlight. Everything else was not great, with special note to the caesar salad that was possibly the worst I've had - chewy, oily, herby croutons, no noticeable parmesan, and oily dressing that made the lettuce especially damp. As we had mentioned that we were celebrating our anniversary that evening, we were comped a slice of cheesecake (with a candle!) and our photo was taken and presented to us at the end of the evening.
The Presidential Lounge is probably worth a trip (if you're in Riverside at the Mission Inn), with an extensive drink list and ample bar food menu. A jazz trio performed after 9 or so.
Breakfast was at the Mission Inn Restaurant. Service was spotty, and food was served cold and sent back for warming. After having had two meals at the hotel, we decided to cancel our reservation for the signature Sunday Brunch.
Mario's Place (www.mariosplace.com) is directly across the street from the Mission Inn and looked promising, but we were amidst wedding festivities and weren't able to give it a try.