From Kotor 1, my favorites are HK-47, Canderous, Mission and T3. I love HK-47's attitude and everything else about him. Canderous is an honorable sort and I liked having him in my party. T3 was cute. I was indifferent to Zaalbar, Juhani and Jolee. Zaalbar didn't do much, Juhani didn't impress me very much, and Jolee was funny at first but it got old quickly. With Bastila I alternated between liking her when she was being nice and really getting angry at her because of her arrogance. I liked Carth a lot when I played through the game as a LS female. Then I played through it again as a DS male and I grew to despise him. How could he leave Mission like that?
From Kotor 2, my favorites are HK-47, Atton, Mandalore, Visas, T3 and Bao-dur. HK-47 is HK-47, enough said. Atton really grew on me and I like him a lot. He survived the evil play-through too (he didn't do anything that made me lose respect for him). Mandalore had the same basic attitude here. I wish the game had done more with him, though. Visas was dark, mysterious and brave. T3 was very cute (again). Bao-dur was nice. I liked having a calm party member. I liked Kreia too but she got me angry at times. I was indifferent toward the Handmaiden and Hanharr. Neither one of them really caught my interest. I didn't like Go-to but his voice acting was very well done. I didn't like Mira because of her attitude and how she dressed. I don't have an opinion of the Disciple one way or the other because I visited Dantooine last so I only had him for a small part of the game.