Oh, I could name a few secondary characters I like very much indeed.
Cat Grant: I think she's my favorite of them all. Pity she was dropped after S1.
Henderson: Somehow, I like is gruff exterior.
Perry: Great shades of Elvis, there's nothing not to like about Perry.
Jonathan and Martha: Definitely. Especially Martha with her weird artiste streak.
Bernie: Yep. He's sorta cool, despite being so nerdy.
I think Jimmy was handled rather badly in the series. There was potential for so much more, but all we ever see him do is fall in and out of love and jump whenever Perry bellows. Well, and come up with stacks of research.
Other secondaries I don't like:
Dan Scardino and Mayson Drake. *grrrrr*
That lawyer guy who's responsible for the Superman foundation. *yuck*
Ralph... *double yuck*
Lana Lang
