Bombay Sapphire is a gin that doesn't taste like floor cleaner. If I'm drinking gin without a mixer, this is my choice. Granted, it's a bit of a "girlie" taste, by which I mean it probably wont make you gag the first time you try it.

If I'm using a mixer, though, even tonic, I'd go with Tanqueray. I'm sure it's not the best gin out there, but it's good enough to hide behind a hint of lime or a sniff of vermouth.