The Riviera's been on the Strip for FOREVER. I remember driving past it's garish wall of horrible Neon whilst dragging the Strip as a toddler with my parents and their friends.
I most likely never would have gone there as an adult if my brother-in-law wasn't a bartender there and if my friends and I weren't on a mission to show this town a party the likes of which it's never seen!
This place is HARD to navigate. More than once I willed the spirit of DeNiro to guide me through it's gold and neon undulations. Don't try to meet someone here - you will never find them.
My bartender was awesome and didn't charge my friends or I for one single beverage. He's also the father of my nieces and nephew. You may find your trip is more costly. (The drinks are like $4 - $7 anyway - not bad for the Strip.)
The showroom was AWFUL. I went to see an old friend in the Fab Forever show and my brother-in-law got me tickets. Since he did so, we had front row seats. I didn't know that front row seats meant that your knees actually touched the stage. Very interesting. Very uncomfortable for an hour. (The show itself was awesome, by the by. Yay, Beatles!)
I like the Riv for the old school Vegas spirit it still keeps in mind, I don't like it for its poor execution.