I have the basic black delrin suzuki / yoshi ones, nothing fancy but thats why I ilike them. Im not one for the flashy billet or colored ones. My 2 cents.
Ive been told whatever you get get ones made of Delrin, they slide vrs catch like harder meterials such as aluminum etc.. But what the hell do I know, its a very subjective question.
I'm a fan of the Vortex sliders, they look pretty good, nothing to flashy but nothing ugly. plus you can replace the delrin pucks for like 15 bucks everytime you damage one. thats a lot better than spending like 60 bucks or more on a new set of sliders. and i've only hear good things about them too.