For the locals or regulars to answer...

You should be there by 5pm that is if the flight is on time.

Are you renting a car, taking a shuttle or using a cab?   While you should be able to get to the Hotel in approx an hour or less, check-in can take some time as well.   I'd recommend that you not book less than 2 hours after scheduled arrival.  Again, as you mentioned, flight arrival can screw ya....

But your flight could.

You did.

My experience is checking in at hotel can be time consuming even at the 4/5 diamond hotels !Consider that along with flight delays , the distance is relatively short , 30 /40 minutes from departing flight at most !Why risk a rushed experience when it should be a very enjoyable experience ?  

-- Modified on 6/13/2013 9:56:21 PM

Agreed with most here.  If you take a cab, it's about a 10 minute wait to get a cab and then a 30 minute max trip.  It's even longer if you take a shuttle bus.  Then you still have to check in.  If you're getting to the hotel around 4:30-5pm, that's when most hotels start allowing check-ins (3-4pm is most common in Vegas), so expect a heck of a line.  Safest thing to do is to not book a date until at least 7, 8 preferably.  8 will give you plenty of time to get there, check in, unpack, get comfortable, take a shower and relax a little before having some fun.  7 is doable, but you'll find yourself scrambling at the end.  Regardless of what you choose, have a great time!

Its usually about an hour but McCarran airport gets very busy around the 4-7PM time frame esp on the weekends.