Quoted from henrydwh:
The PHOF is definitely now on our list and looking into the neon museum. Want to check out downtown or Fremont street. We are only there for 3 days, so we are going to cram in as much as we can! Thanks to everyone for the input!
Some have already been mentioned, but here would be some things I'd recommend in Las Vegas:
1 ) Walk through the casinos. Since you are staying at the New York, New York start there. On that side I'd try to get to are the Cosmopolitan (Sparkly), Bellagio (Fountains, Gardens, Glass Ceiling), Caesar's (Fountains, Forum Shops), Mirage (Volcano) and Treasure Island (Pirate Show). On the other side I'd probably try to hit up the Venetian (Indoor Canal) and Paris (Eiffel Tower, Arch). Everything mentioned above is free, but you can also check out the resturants. One of my favorite places for a cheap lunch or late night snack is Secret Pizza in the Bellagio. It used to really be a secret, as it was behind an unmarked door, but now it's easier to find. That's a lot of walking, but I kind of treat it like "urban hiking".
2 ) Go to a show. They are expensive, but in my view they are worth it. I've been to quite a few of them, but the two I'd recommend most are Absinthe or LOVE. Absinthe is super raunchy and offensive, but beyond that it's basically a circus that takes place on a stage the size of your kitchen table. LOVE was my favorite of the Cirque du Soleil shows, but I think a lot of that has to do with the music. I've also done Ka, La Reve, Criss Angle, Mat Franco, and a few of the "Broadway" shows which rotate in and out.
3 ) Go to the Pinball Hall of Fame. I think it's worth it and it keeps you from feeding the other machines that tend to take your money more quickly. I sometimes go a second time when others in my group just want to sit around.
4 ) If you want a fun place to gamble and drink I really enjoy the Sigma Derby horse racing games at The D or MGM Grand. Since you are staying at the New York, New York the MGM Grand is right across the street. It's basically a mechanical horse racing game from the 70s that takes actual quarters. The game itself is really only fun if there is a fun group around the table. Drinks are free and if you tip they will be back.
5 ) Get a stake and drink some microbrew at Ellis Island. Someone else mentioned it, but if you want to feel like your getting a good value it's a decent option. I want to say beer is $1 and the stake meal is like $10. With that said, there are no shortage of good food. Feels a bit like a local spot.
6 ) Go to Freemont Street...maybe. A lot of people swear it's better then The Strip, but personally it feels a bit dirty. Still lots of lights and neon. The best part of it for me is people watching. I describe it as...go to people watch and drink until you become one of the said "people" others are watching. Pro tip, when going back to The Strip instead of calling Uber, check with the hotels. Sometimes they have a vehicle sitting around and they will give you a ride back in a luxury vehicle (ex. stretch limo with free booze) for the same price.
7 ) If you want to get away from Las Vegas there are several options. Red Rocks is about 30 minutes away and has some decent hiking or rock climbing. Then there is, of course, Hoover Dam. It's about 45 minutes away. I don't feel the need to do the tour again, but if your interested do it. The last time we just walked across. If you are into hiking there is also the Gold Strike Hot Springs trail which winds it's way (for like 3 miles) down to the river. It has some rope sections, which are fun if you are in mediocre shape or better. If you have a suit you can swim in the natural hot springs or wade in the ice cold river. Finally, there is Zion National Park. I like the Narrows and Angels Landing hikes. That's about a 3 hour drive, so it's going to be a full day. Oh, I should add all of these would be a bad idea if you are going in the summer...too hot.
8 ) Buy your own booze at Walgreen's / CVS and request a "medication fridge". We stayed in a sweat at the MGM and it was kind of funny checking in. I asked if we could get a fridge and they guy said, "Do you have any medication you need to keep cold?" Without thinking, I answered, "No". He asked again, this time with a little wink. My wife jumps in and says, "Yes, we do have medication we need to keep cold." He's like, "I thought so, I'll send one right up for you." My wife then asks him if there are any other questions like this that we should be asking. He said, "Since your room is not ready, you might be upset and hungry, I could then offer you a dinner voucher." We suddenly remembered we were upset and hungry and he put $100 credit onto our room to cover dinner. Also we found the two bedroom sweat to be a good value, when staying with another couple, since we only had to pay one resort fee.