We have visited LV many times (including last year when we renewed our wedding vows with Elvis - thanks DH). We prefer to stay in a different hotel each trip and on several trips when we have gone onto other states and then returned to LV we stayed in another different hotel then too!
We have stayed at Luxor (my fav) and Excalibur (absolute hate this one - way too smoky EVERYWHERE but has Tournament of Kings live show which is worth a single visit, stay clear of the Fun Faire in the basement - understaffed and old and tired) both several times. We have also stayed at Rio Suites (off strip but is affiliated with Paris and Ballys so has a shuttle to strip and an awesome "World Buffet"), Tropicana (same corner as Excalibur, NYNY and MGM), Sahara (gone now and at cheapest end of strip, was great for travelling further out of LV on day trips), Stratosphere (fantastic attractions at the top for the thrill seekers but very costly - find coupons for rides, rooms very cheap), Circus Circus (stay away from here, cheap and old rooms, great adventure dome and terrible garden buffet), Imperial (fantastic mid strip location, short driveway/less walking, clean tidy rooms, boring pool area, cheap), Flamingo (lovely decent priced buffet with lots of seafood and variety of other foods, mid strip perfect location, found good price on online discount company), Aladdin (now Planet Hollywood, has great shopping, good array of food choices and spacious pool area),NYNY (we love the coaster and more importantly Krispy Kremes in the food court-lol), Caesars Palace (pricey on Fri/SAt/Sun but great location, fantastic high end shopping - save your $$ for the outlet place near the airport), MGM (spacious rooms, average restaurants, big casino floor with great selections) and I think that's all we've stayed at...
I would like to stay at Monte Carlo or Paris next - I have budget taste! However I don't even have a US trip planned right now (DH is going staying at the Luxor in January and then going to DL with his friends - OMGosh!)