Zildjian cymbals are considered to be the best (or tied with
Sabian, another company started by one of the Zildjian brothers).
Zildjian offers cymbals manufactured from two distinct processes:
Cast bronze
Machine-stamped sheet bronze.
The two processes are divided into several lines of cymbals.
Cast Bronze
Each cast bronze cymbal is unique, so it is suggested you bring in your other cymbals to so you can play them all together.
K Custom
The K Custom line references the original Turkish dark tonal colors. The attack is penetrating, and the range is very broad. Performers who use the K Customs include Steve Gadd and "Smitty" Smith (Tonight Show Band).
K Zildjian
The K Zildjian line has a darker tone with a wide range. The original Turkish line is now the K. These cymbals are very versatile, and are particularly suited for jazz and fusion/funk. Performers who use K Zildjians include Peter Erskine and Dave Weckl.
A Custom
The A Custom line is closer to the classic 1940s to 1950s sound. The tones are brighter than the K lines, and the A line is made with an exclusive rotary-hammer technique. Performers who use the A Customs include Carter Beauford (Dave Matthews Band), Vinnie Colaiuta and Simon Phillips.
A Zildjian
The A Zildjian line is the worlds most popular cymbal according to Zildjian. The A Zildjian line runs back through history, "from Beethoven to the Beatles." There are more weights and sizes available in the A Zildjian line than any of the others. Performers who use the A Zildjians include my favorite drummer, Neil Peart from Rush.
Z Custom
The Z Custom line is newer. The cymbal is computer-hammered. These are one of the most durable of the cymbals that Zildjian manufactures. Tailored for Heavy Metal, Rock and Alternative drumming. Performers using the Z Custom line include Lars Ulrich (Metallica), Taylor Hawkins (Foo Fighters) and Joey Kramer (Aerosmith).
Machine-stamped Sheet Bronze
Edge
The Edge series have a higher pitched cutting sound. The cymbal also has fast decay times, and excellent projection.
ZBT and ZBT-Plus
Generally considered to be "beginner" cymbals, these are least expensive. If you are going to invest in cymbals, I suggest buying a professional cast bronze set once and skipping the kiddie set. It is an investment. The ZBT lines have fast decays and a brilliant sound, but lack the tones and range of the professional lines.
Zildjian cymbals are available in a traditional satin finish or a brilliant polished version. From personal experience, the polished versions show fingerprints easily and require constant polishing. The satin versions have a brighter tone because some of the lathing has not been worn away from the polishing process.
Zildjian also makes special effects cymbals, such as chinas, swish knockers and gongs.