I've stayed in just about every hotel imaginable with work... from really nice places to gross motels in the middle of nowhere.
But when I pick a place to stay myself (if I'm paying and not using rewards points), I choose a comfort inn (or sometimes their sister chain, Sleep Inn). While there's nothing fancy about them, the rooms are squeeky clean, the hotel staff is friendly, and they take care of you.
Beyond the pool and excercise room, don't expect a luxery stay. Breakfast is mediocre, the lobby is small, and the bathroom is a standard hotel bathroom. But you NEVER have to worry about cleanliness.
I'd recomend just about any Comfort Inn in the country... prices range from $50-$90 a night, but it feels like a $100 room.