Ok, some facts. I dabble in voice actor listing and memorize them all
Collette has not done much VA work yet. She's done some "The Land Before Time" movies where she had Ducky's role. She's also done Miyuki in Xenosaga Episode 2.
Presea is Rikku from FFX(-2). She's also Bubbles from Power Puff and Sakura Mizrahi from, again, Xenosaga Episode 2.
The voice actor of Genis is actually a woman by the way. She's also KOS-MOS from, guess what, Xenosaga Episode 2 and did mostly Digimon stuff before that.
Sheena's voice actress... You may remember her as Bastila Shan from the KOTOR games. I know I do
Also... She's Samus Aran of... I don't need to say what Samus is from do I? Apart from that, yep, a Xenosaga Episode 2 role although not as significant.
Raine. She's Pellegri and Febronia in Xenosaga Episode 1&2 (one of the few VA that weren't changed) as well as Mirage in Star Ocean 3.
Zelos, whom you all love it seems (so do I) has done next to nothing aside from ToS. It seems either nobody wants him, he didn't like the VA business himself, doesn't have a voice anymore or died. Too bad though, I love his work.
Regal is ooooh, I'm gonna say it, Albedo and Nigredo in Xenosaga 1&2, Albel in Star Ocean 3, Balmung in the .Hack Series (games and series).
And finally Kratos. As mentioned before he's Ryudo in Grandia 2, but he's done many more major roles. He's even Liquid Snake of... You all know that too. He's done many many roles in Bioware/Black Isle games (think BG series, Icewind, Planescape, KOTOR, ...).
And another Xenosaga 1&2 appearance is young Mithos, he played Jr. There, that's it. Hope you enjoyed the read.