WUV WUV WUV.
I always hit up ABC stores for some hard liqs/bubbly for my Vegas nights! The bottles are not extremely overpriced and the selection cannot be beat. They also have a good variety of snacks; some that you cannot even find in NYC (Hot Funyuns baby!)
Also, if you are a broke phi broke college student like I was my first time in Vegas, they also sell some decent prepackaged sandwiches for something redonks like $4. Not a bad option if you are trying to save some moolah :)
Choice of free Las Vegas tote or mug if you spend $100+!
I also bought this ridiculously adorable Hello Kitty in a flapper costume in front of a slot machine key chain from here. Amazing.