BioWare. Ever since they developed Baldur's Gate, they've really captivated my attention with every release. Their games are smart, funny, and inventive. Mass Effect is only the most recent of their accomplishments, and it's currently living in my 360 with no sign of relinquishing its spot. Half-Life and Portal are good, but they just can't measure up to the long string of hits in BioWare's library.