Vegas is always a great time, especially if you can afford to stay in a good hotel. Even a dumpy one aint bad because there's so much to see everywhere else.
First time I went, I stayed at the Imperial Palace which is a dump. Still, they have a car museum packed with historical cars. I was in my 20's so walking everywhere wasnt a problem. The Luxor had some great attractions then too.
When I was in my 30's, I went several times for work. Was able to attend the SHOT Show one year and that was awesome! I think thats when my wife and I first discovered Mon Ami Gabi. What a great place to people watch! The food is great too! Star Trek The Experience was at the Hilton back then and it was great if you're into Sci-Fi. Had many drinks at Quarks Bar, including the Warp Core Breach which has a shitload of alcohol! One night, we went to the night club at the top of the Rio which was a blast.
In my 40's, I went to SEMA several times. Also went to a few art galleries and saw famous paintings, sculptures, etc. Went to several shows which I hadnt ever done before. Ate everything from In-N-Out to whichever high dollar restaurant was at the Bellagio at the time. I didnt even spend much on gambling.
Late 40's/early 50's I've switched to only staying at the Augustus Tower Caesars, Bellagio, and once at TI when they had a Strip View suite that was about 1000sq ft. I rent cars and valet park instead of walking everywhere. We always go to the Peppermill at least once. Its been in a bunch of films and has a fireside lounge thats funky. The shopping is as good as anywhere I've been including Rodeo Drive.
Vegas has something for everyone and if you cant have a great time there, you arent looking to have a great time there.