Whoa, whoa, whoa... sorry guys, but there are just a ton of HORRIBLE suggestions in here. The Flamingo? Hooters? BALLY'S???? Seriously? Come on guys. He said he's going with his wife, not his junkie cousin Earl.
I've stayed almost everywhere on the strip. Well over a hundred trips to Vegas, some for months at a time. I know the town well. Here's a fair breakdown for you off the top of my head...
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High End Casinos:
1) Palazzo - Super nice rooms. Might be my favorite place to stay. You get a sick suite for $129 per night Su-Th and $179 Fr/Sa if you play poker at the Venetian for 6 hours per night between the two of you. If you play, this is one of your best options. If you don't play, these rooms are $400-500 per night, so they're off the table if you're not playing.
2) Bellagio - Pretty much the same deal as the Palazzo, but I think they only require 5 hrs of play per room per night. Super nice hotel though. Blown glass in the lobby by Dave Chihoulee (sp?), marble shitters with granite doors, comfy sports book, just a really classy place overall. But this means higher stakes on table games if you're a gambler.
3) Wynn - Really high end place. I don't really like the crowd that hangs out there. Super stuck-up and poshy. But they have a Ferrari store/dealer inside. So... there's that. Stayed there during NCAA March Madness. Was pretty sick. They turned their theater into a huge multi game March Madness madhouse. Was pretty great. I play in their smallish card room from time to time. They occasionally get some good mid-stakes mixed games going. It's worth checking out for that IMO.
4) Caesar's Palace - The place to go if your wife loves high end shopping. Also cool to walk around. This place is huge, but it's getting a bit dated and doesn't really belong with the casinos above in terms of price, but somehow they still pull big money. Not a great option for me, but I've stayed there a couple times in the past. It's still nice.
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Nice Casinos:
Venetian - I really like the Venetian. It's classy, but not overly so. Women usually like it as well. It's in the higher end of casinos, but not quite as pricy as some of the options above. Again, you can get a poker rate here, but if you're playing cards, go over to the Palazzo instead.
Mandalay Bay - This is the best place on the strip if you plan to spend time at the pool. Their pool is AMAZING! It's actually more like a water park than a pool. They have a fucking wave pool, and a lazy river with inner-tube floaties. Great spot. Poker is somewhat lacking here, but it's hard to go wrong at the Mandalay Bay.
Cosmopolitan - I fucking hate this place and refuse to stay here. But people love it. It's basically Sex and the City the Casino, and the crowd that comes with it. If that appeals to you, along with purple and blue neon lights in a dimly lit bar with girls in sequin dresses and guys wearing suits and shitloads of Axe body spray, then this place is for you. Oh, they do have a good pizza place upstairs though, so there's that.
Aria - Is becoming a big spot for poker, specifically for NLHE low limit players. They have good poker rates as well, but might be above your price range if you're not playing cards. There are better places to stay. Somewhat similar crowd as the Cosmo, but not as bad. It's a lot of younger people here. Tons of 21 year-old hot-shot poker players. Some of them are quite good, most are not. Be careful playing cards here. But if you're a good player, you can make some loot for sure.
Monte Carlo - This place is a good option as well. Not the nicest, but it has some class and the rooms are comfortable. A good value.
MGM Grand - Pretty decent place. They have some nice rooms, but this place is MASSIVE. You can walk about a full mile just trying to go from one end of the casino to the other. It's not overly fancy though. It's a bit plain for my tastes. No real theme to it. It's a little overpriced for me, but still a good option.
Planet Hollywood - This is the old Aladdin place redone. They've done a really nice job with it. It's centrally located too, right across from teh Bellagio and attached to the Miracle Mile Shops. Plus, there's an Earl of Sandwich here, which is a must eat place as far as I'm concerned. Great hot sandwiches for about $6. This place is one of the best value spots to stay on the strip IMO.
Paris - It's a pretty nice place, but it's really small. You'll like your room, but you probably won't be spending much time here.
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Mid Range Casinos:
Golden Nugget - This should be your only option downtown. I kind of like this place. A little nostalgia, and nice enough for me. They remodeled the place a while back, and I think they did a nice job. However, you're away from the strip if you're downtown. But you can take a double decker bus right into the strip if you want to.
The Mirage - Meh
Treasure Island - Watch the Pirate Show and move on
New York New York - Try the pizza joint inside. Walk around a bit. It's ok, but not great. Oh, and there's a rollercoaster... so there's that
The Luxor - This place is actually not very nice, but it's not in the "Complete Shithole" category either. It's ok if you're on a tight budget.
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Complete Shithole Casinos:
The Flamingo - Don't do it. Trust me. Just don't do it.
Hooters - It's not what you think it is. Trust me! This place sucks
The Riviera - Is this place still open? I sure hope not
Stratosphere - LOL
Bally's - Great location. That's about it. This place is disgusting inside. The prices are cheap as hell, but your wife will be quick to point out why as soon as you walk through the lobby.
The Excalibur - Meh... not worth talking about much. It's just a centrally located super cheap hotel. Not bad if you're on a budget, but you won't be spending any time there.
Tropicana - They remodeled this place a while back. I hate it. One of the worst values on the strip IMO. Go elsewhere.
Anything else downtown besides The Golden Nugget - Don't do it... you'll regret it. Even Binions sucks. Some people like "The D", but I don't... see what I did there?... see it?
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Other options / some off the strip places
South Point - This is several miles south, but still on Las Vegas Blvd. It's nice inside, and a good spot to stay at if you want to save some money and get away from the madness on the strip.
The Hard Rock - It's alright. Good pool parties. This place can be fun on weekends. But I haven't stayed here. Probably never will.
The Palms - They try hard to cater to the MTV crowd. There's a cool glass floor bar/club way up toward the top of the tower that's pretty cool. Decent option if you're more into partying. Probably can find lots of blow here lol.
Rio - Fuck the Rio
The Orleans - Lots of low stakes action here. I actually really like this card room, but it's a fucking smoke factory in here. Tons of old people too. Like really, really old people that just keep pressing "Bet Max Spin" over and over on those damn slot machines, just waiting to die. You will completely reek of smoke though if you even set foot in the door, so be prepared. I wouldn't stay here, but I have played here several times. They have a good weekly HORSE tournament on Sunday nights.
Avoid other places off the strip for the most part
...I'm sure I missed several, but this is a pretty fair list to start off with