The lines can be roughly and somewhat arbitrarily divided into three categories:

Most suitable for Jazz :   Nostalgia, MC Jazz,  Mehmet Legend, Turk, Vezir,  the Tribute and Anniversary Rides, Origin Dark  ***   Most suitable for Rock:  Radiant,  Murathan,  Funky Rock  ***  For All Genres: Traditional,  Sultan,  Marmara Onurhan and Emirhan, Origin, Vezir,  Mehmet Legend, Legend Dark, MT Anniversary Ride


Traditional
  Fully lathed, the classic Turkish cymbals, the "Avedis" of  IM, with the widest variety of models and sizes: crashes from "paper-thin" to "heavy" weights, 6 different rides,                4 kinds of hats, splashes, bells, Chinas, Pangs,  the works...

Sultan
  Stripes of lathed and unlathed on top, unlathed bell, lathed on bottom.  Among my personal favourites. Great balance of energy and dryness, like good champagne. The crashes tend to be medium to medium-thin, feel light and airy, and have relatively little tonal body with perfect hissssssss ! Terrific in the studio, but loud enough for most  un-miked gigs (except Heavy Metal and the like).

Marmara
  Wider stripes of lathed/unlathed than Sultan,  more heft , volume and tonal body;  nicely "explosive" without being overpowering. Two separate lines w/ different lathing patterns: the warmer, drier  Onurhan,  and the brighter, more cutting/piercing  Emirhan.  Crashes tend to be medium-ish: weight- and  sound-wise right between Sultan and Murathan. Great all-rounder series .

Radiant
  The Rock series, highly polished , mostly heavier, with  more tonal body, and louder than other lines , cymbals of choice for rockers all over Europe. Radiant Traditionals have the classic lathing pattern,  Murathan models (raw/polished) are designated specifically for Hard Rock  and Metal (ala "Rude"), can take hard hitting and can be very loud, but -being handmade Turkish cymbals- they also respond to a softer touch, and easily shine in other genres. The crashes- medium to full- tend to have a full-bodied "explosion" with a clean finish,  sound  and feel nothing like the  clang-y "rock crashes" of the Mac-(dj)ians.  "...Heavy metal thunder.."
                                                                                                                                                                                                                                                                                                                              Nostalgia 2010
Nostalgia
 See independent  review at  http://www.drumdojo.com/istanbul_nostalga_2.htm .  As of  2010 the Nostalgia series has been reworked: a slightly changed
profile with a more gradual  transition from bell  to bow,  and a small traditional logo- all  reportedly done by Mehmet's "Special Production Team", headed
by the man himself, which now handles all the high-end lines.
                                                                                                                                                                                                                                                                                              
Mehmet Legend/Legend Dark
  See independent glowing review  at http://jazztimes.com/articles/14202-istanbul-mehmet-legend-cymbals .  "..perfect traditional jazz cymbals.." ( the Mehmet equivalent of  Agop's  Mel Lewis series),  but I happily use the 19" C/R in a rock band setting, and love the precise stick definition over the controlled silvery wash.  I also really like the new  Legend Dark (2009) series. The rides are sort of  "a less wealthy man's" versions of the MT Anniversary Ride (similar lathing pattern, but raw bell, and heavier)  at around $200 less .
                                        
X-perience
  Haven't seen or heard them in person. Pricey.  The  X-Jazz Mehmet Sign. Dark  Series (20" Ride, 14" Sizzle Hats) are a limited edition w/ only 250 pieces per model made.

Origin/Origin Dark                                                                                                                                                                                                                                                                                                                                                        A more recent series, the medium weight, fully lathed Origin, and the lighter, unlathed, heavily
hammered Origin Dark.  Beautiful high-end cymbals w/ rich musical sounds.  Rides, crashes, and hats available.  
                                                                                                                                                                                                                                                                                                                                                                                 Legend Dark Ride
MC Jazz
  Yet another gorgeous jazz series, introduced at NAMM 2010.  Raw smooth bell, deep dark lathe pattern top and bottom, described as a dark version of the Mikael Z Ride -same profile.  Dry, dark. "washy", vintage.  20", 22" Rides, 18" Crash, 14",15" hats   The cream of the crop: Mehmet's tribute to his former employer and teacher Mikael Zilcan, and his celebration of making cymbals since age nine (they do have child labor laws in Turkey by now).  Both rides available in 20" and 22", with or w/o  factory-installed rivets.  Same profile with a smooth bell bridge. The Tribute Ride is  a typical classic smooth and "washy" jazz ride, the Anniversary is  darker  w/ different, unusual lathing on top, and possibly more versatile in application.  They  received  much praise in DrumMagazine's Soundlab Review (12/09) for refined musicality, versatility, and- yes - "looks".  The Modern Drummer Reviewer (7/09) preferred the 20" sizes, and found them to be "the closest replications of old Ks I've ever heard". If money is no object, or you are a serious jazz player and/or collector,  go get them. I'll try and discount what I can...If you can't afford to spend half a month's rent or more on a cymbal, there are other, more affordable choices.                                                  
 Sound files are >> here <<