I usually go to West Middlesex Hospital, but since I was passing through the area for work and I don't have many annual leave days left, I just walked into Heart of Hounslow GUM.
The receptionist was bloody gorgeous I have to say. I filled out the usual paperwork and was called in within 20mins. The nurse asked me the usual questions, took my blood, gave me some condoms and then gave me the tiny container to piss in.
Checked my watch as I was leaving and I was in and out within 42mins! The results took 2 weeks though, all negative (clear!). Previously, West Mid took 5 days for results but I was in the clinic for at least 2 hours. I was sure I had nothing to worry about, so I don't mind waiting for results as long as I'm not sat in the waiting room for so long!