Only the movies and Clone Wars Cartoons are still cannon. Everything else, including KOTOR and the Force Unleashed isn't.
I'd also disagree with most of your list:
Ben - rather boring as an actual character. Good concept for Luke's son though.
Cade Skywalker - Haxxed powers and an attempt to make SW darker and edgier. I won't miss him.
Rahm Kota - Dull mentor figure from a game with a terrible plot. Not bad persay, but not worth saving
Darth Bane - Is still cannon as he was in The Clone Wars
Jacen Solo - Controversial. I actually liked his fall to the dark side, but am in the minority.
Exar Kun - another haxxed Sith with ridiculous powers and little personality. Again, not particularily bad, but not very good either.
Starkiller - No. Just no. Another stupidly overpowered character who only makes sense as a video game character to enable the player to get into epic fights. Then he got worse in 2.
Here's some alternatives:
Grand Admiral Thrawn - should be obvious why
Mara Jade - again, a shoe-in for the list
Kyle Katarn - another clear shoe-in
Baron Soonter Fel - Basically the anti-Wedge Antilles. Leads the Imperial equivalent of Rogue Squadron, and had to deal with the breakup of the Empire
Corran Horn - Controversial and arguably a creator's pet, but I personally enjoyed the idea of a cop turned Jedi and different perspective he brought to the New Order.
Borsk Fey'lya - An asshole, but on the Republic's side. Democracy's great and all, but it also comes with its share of warts, the biggest of which is this guy. And in the end he went out with a bang.
Lieutenant Kettch -
Easily the best character from the EU
Edit - Warlord Zsinj too. Awesomely mercenary, and his pretense of being a bumbling fool was hilarious.