The KotOR series of course! Two of the best RPGs ever, and with storylines better than the prequals.
Second place is the Jedi Knight series.
2Cold Scorpio, Rogues' Guild class 1A
"By the ancient spirits' rites, the old ghosts proclaim their rights; still they're lost in time." -"Blood on My Hands"
, Demons & Wizards
"We'll build a perfect beast with the knowledge they seek; if it takes ten thousand years, we never will retreat!" -"Prophecy"
, Iced Earth
"If you'll pardon my stealing of movie lines: The Force is with us" -Ronald W. Reagan