When it comes to guitars and basses there are (obviously) a lot of factors that go into the tone/sound of the instrument. The wood, the type of hardware (nut, bridge), and the pickups all impact the sound that you get before you pick an amp.
A lot of stock pickups are pretty darned good. Gibson's got a good line, Aria actually has some good pickups they use, my Kramer Custom has a nice set of pickups - and the classic Ibanez pickups from the 70's and early 80's are fantastic, too! Hell, for that matter the Matsumoku MMK45's are excellent as well! (As are some of their other pickups.)
But to get the exact tone you want sometimes you have to go aftermarket, and that's where a lot of companies do a lot of great work.
DiMarzio and Seymour Duncan both have some great pickups with a WIDE range of tones and output levels. Tom Anderson pickups don't have that kind of selection, nor do they have as wide a range of tone & output levels, but Anderson pickups are VERY good.
There are other, smaller companies as well that have some great pickups if you're looking for a sound that you're just not finding anywhere else.
Over the next few weeks we'll post some examples of recommended pickups from various companies.
This one has a crisp, punchy sound that really cuts through. It definitely works well for leads if you want them to stand out. The one gripe I've got about the Evolution pickup is that it is a little thin. It's got a great warm midrange, and good high end (crisp, clear, but not to harsh), but the pickup lacks a good bottom end. The low frequencies are pretty weak.
It definitely sounds like a late 80's Ibanez kind of sound. If that's what you like then this is a great pickup for you.