I love good old Watson from R/S/E. He had a cheerful personality and shows you can't be too old for a Pokemon battle. He was actually the first challenge I've had against a gym leader for a while. He also trains the shocking Electric types, my favourite type after fire :3.
And I adore the gifts he gives out. For example,after you get surf and you do this tiring task in New Mauville you get the powerful Thunderbolt xD.
Other than him, I love Jasmine how she attempts to heal ill Pokemon and comfort them like shown in the Lighthouse. She is a beautiful young lady who really knows how to express herself xD.