Inkers tend to fall into two types: Illustrative (the ones who strive for photorealistic results; look at the Adams/Giordano collaborations, or the Colan/Palmer ones) and Graphic (fewer, thicker lines, more spot black, no attempt at photorealism. See: Alex Toth, Klaus Janson, Howard Chaykin, Walt Simonson, Alex Nino). Terry Austin, whose stuff was insanely popular from about 1978-90, had elements of both types.
It might be best to focus on the different inkers who have worked on a single penciller, like Jack Kirby or John Buscema.
Kirby has gotten all the major inkers, including several who were pretty strong pencillers in their own right (Wally Wood, Barry Windsor-Smith and Herb Trimpe, for example). He also got a lot of journeyman hacks who were fast but uninspiring (Vince Colletta was the most notorious, but I think Frank Giacoia has a lot to answer for). Probably the best were strong stylists who streamlined Kirby’s style and turned dozens of hash marks into a single, strong line, like Joe Sinnott. Sinnott also championed the use of Spot Blacks and Kirby Krackle, signature moves more often attributed to Kirby. When Kirby got to pick his own inkers, his preference was for Mike Royer, whose inks basically just traced the pencils without trying to enhance them.
Buscema got most of the same inkers Kirby got, with much of the same results. He also got more “illustrative” inkers like Tony deZuniga, George Klein and Tom Palmer. I’m not sure whether Buscema ever got to choose his own inkers or not. His work on Conan saw great variety in inking styles, and I think the best inking he ever got was from Alfredo Alcala, a strong illustrative stylist in his own right.
You might want to check out chapters 3 and 14 of the Famous Artists Cartooning Course for a better discussion of this than I can give you.