What type of rods do you currently own and really like? Do you have a specific brand that you currently have and like? As MP said, some like fast action, some like medium or even slow action. Are you getting this for a specific purpose, or as a general purpose rod? What kind of flies/sizes do you expect to be tossing with it?
For reference and a list of some of the rods you might want to consider, the 5wt shootout is a worthwhile read though dated just slightly. Some models may have changed since publication, and remember, this is merely opinion. YOUR opinion is what counts. If it were me, I'd make a shortlist of the rods under $500 that interest me, then go to the shop and try them.