Would have to have been Pete's Wicked Ale which was the first ale I drank in any great quantities (and frequently on special at my local poolhall back in those days). I eventually became a big fan of microbrews and various styles of ale.
To be honest though, I had a relatively narrow scope until ~5 years ago when some friends I decided to get 'plates' at the Flying Saucer and drank 200 different beers. I definitely broadened my horizons that summer.
My younger years (under 21) it was Olde English, Mickey's and anything that I could just get drunk from, I think there were a few gallons if gut rot wine in there as well, around my 21st birthday the local store had a few different sixers of Pete's. Then I started my world tour (thanks to the Army)
Spokane, Wa ~~~~ Pete's ales and Lagers
Columbia, SC. ~~~~ Shiner Bock
Lawton, Ok. ~~~~ Flying Dog brews
Ft Irwin, Ca. ~~~~ Seirra Navada and my first book on homebrewing
Uijeongbu, South Korea ~~~~ Diebel's, Hite, Cass, Soju <~ Bad stuff, but in a good way
Spokane Wa. ~~~~ The eye opening offerings of Stone Brewing
Seattle-Tacoma, Wa ~~~~ micro brews of many different types
Ireland ~~~~ Guinness fresh from the tap while watching "football"
Iraq ~~~~................
Tomah, WI. ~~~~ New Glarus, City Brewery, Leinenkugel, I hope to go and see a few more!
I am sure there are a few places that I forgot Germany, Japan, Guam,
but over I can thank Pete's Wicked ale...
-Jason