I was there about a month ago and I stayed at The Holiday Inn and Suites in the Zona Rosa. I got a really good rate for a suite and it turned out to be a really nice little place. About a 10 minute walk to the bars etc, but in a nice quiet neighborhood on the edge of the Zona Rosa. Anything in the Zona Rosa or close to it would fit your bill, it just depends on your budget. All of the hotels mentioned in those other threads are all good choices.

If I were to go back, I would take a serious look at the Sheraton Isabel, the location is perfect for walking to bars, sightseeing and connecting to public transport. Roomate Valentina is right in the center of it all and too close to all the noise for me. There was a hotel in the NH chain in the Zona Rosa that also had a great location as well. There were quite a few choices in that area that have good reviews on Trip Advisor as well.

A tip on the bars and getting home, if you choose a hotel where you would need a taxi to get home, always ask the bartender or other bar staff to call you a taxi. They always seemed to have someone on call with good fair rates as opposed to flagging one down or going to a taxi stand where they will charge you a few more bucks.

Enjoy Mexico City, I had a great time there!