My fav is the Marriot on S. Figueroa. Clean, reasonable, good location.
Westin Bonaventure is right across the street.
For happy hour try the Standard. Really upscale trendy kinda place. Around the corner from the Westin.
If you want cool laid back I love this place The Figeuroa
http://figueroahotel.com/, right across from the Staples Center and 3-4 blocks from the Morrison Hotel, yeah that one which I do NOT recommend.