Vegas hotel recommendations please?

Hi all, I'd like to ask for some opinions on Vegas hotels. I'm heading home to Utah (from Cali) tomorrow with my bf. I want to surprise him w a night or two in a great vegas hotel. I've found some really good deals but I'm just not familiar enough with the hotels. For example, I can get 2 nights in a luxury room at the Stratosphere for under $100, or I can stay at a higher rated hotel-- like Mandalay Bay-- at the same price for not quite so luxurious a room. A comfortable room is key more than location. Any suggestions? Or any great promo deals you know of?