Jacen wasn't in a game but he is canon. Some of his stuff isn't canon though, or at least ambiguous.
"After feedback from George, we decided on Jacen as our 'hero' and the character who would undergo the most dramatic changes—in many ways, the NJO is really his series. At those meetings, we charted the character threads for each of the main characters and how these threads would interact with Jacen to show him as an indecisive young man who grows into a strong and confident Jedi."
―Sue Rostoni
Revan is like 20th. He was a masterful leader, and if I was going just by the game, he'd be about twice as powerful but Drew Kapysharan wrote a novel, cutting his power by having him lose to a relatively weak Sith Lord. Same goes for Meetra Surik, who despite killing the three Sith who enslaved a galaxy, drained a planet of billions life force and a sorcerer who manipulated them all, still died against a mediocre bruiser/powerhouse Sith and an alchemist (maybe vitiate can be a sorcerer but I regard his powers more in line with an alchemist).
However it is of course difficult to judge the respective powers of Old Republic Era Jedi, Clone Wars Era and New Galactic Republic Era. Each time the writers just want to 'out-do' each other and make theirs the most powerful. But nobody beats Luke.
