Colo recommendations

I'm investigating colocation space in the following cities
Irvine, CA
San Francisco, CA
Las Vegas, NV
Phoenix, AZ

Does anyone have recommendations for (or against) any specific colo? I'll need
1/3 rack, 16 amp power (or 8 amp 220V), fiber cross to 1GB ISP upstream (haven't
chosen the ISP yet, either), roof or tower access to mount an antenna.

Private replies are welcome, as are replies to the list.