Arcade: Galiga and Dragon's Lair! Spent about $300 USD in quarters on each at the local arcade!
Online: Got hooked on calling BBs boards around the USA. Ran up a $963 USD phone bill (I still have that bill!) for a single month...disconnected and put away the 300 baud(!) modem after that.
Online Games: Alpha/beta tested The Realm Online. Stayed there for 10 years.
Stand-alone games: Bards Tale (the original version), the Wing Commander series including Freelancer, and the Baldur's Gate series!
GW2: Yak's Bend - Dolnor Numbwit, Elondra, Festoon Turnbuckle
LOTRO: Gladden - Dolnor Numwit, Elondra Numbwit
TSW: Elondra "Clorisa" Numbwit, Noldor "Dolnor" Numbwit, Festoon "Swivel" Turnbuckle
City of Steam: Whatever needs testing (ie: DolnorGoblin), Numbwit on forums
SWTOR: Dolnor, Elondra, Noldor