I do not drink any alcohol at all anymore; but I used to enjoy gin.
Tanqueray, Beefeater, Bombay Sapphire, and Gordon's are all good.
Or better yet go to your local liquor/spirits store and look at different brands and prices.
A really good gin drink besides a gin and tonic, or gin martini, is a gin buck which is gingerale, gin, and lemon juice with ice.
A Singapore sling is also very nice.