NFI is pretty close to my ideal bar and is THE hangout spot when I'm in Vegas. I don't dance, so nightclubs aren't a great option to drink and hang out at and most bars are too loud or crowded with no where to sit.
NFI is great because it is huge, has outdoor areas to escape the noise, tons of seating and an incredible band playing live music for hours 6 days out of the week. I recommend going to listen to Ri Ra, the house band if you haven't done so already. They play great folksy Irish songs and drinking songs that make even the most Mexican guy (me) feel Irish.
If you're not into clubs or just looking for a change, check out NFI. Put down a couple pints, request "7 Drunken Nights", sing along, and be merry.