For Kotor I: I used scout to level 5, then sentinel. The anti-paralysis is great so you will never be knocked out when you must act. The other classes have too few feats or to little force energy.
For Kotor 2: Sentinel or guardian are equally favored, but my guardian has intelligence pushed up to compensate for the skills. I always favor only the Weapons Master because the Feats and advantages increase as levels increase. Force energy is rarely depleted, so master and councilor are not used.