Exactly. Keyswitches are the biggest difference. Everyone likes different types of keyswitches. From what I can recall, there's:
Cherry MX/ML Black, Blue, White, Brown, etc.
Each one has a different combination of clickyness, tactileness, and stiffness. Just about any keyswitch will feel better than a rubberdome, but you won't know which ones you prefer without trying them all.
There's also other things to consider. USB vs. PS/2 (PS/2 is preferred because it's a fraction faster and allows for NKRO, but USB is more convenient), matrix design (NKRO/6+4 (on USB) means all keys can register simultaneously, otherwise certain combinations may not work), sculped vs. flat (sculpted is usually more comfortable), number pad or no, backlighting or no, and construction quality. Everyone has their own preferences on most of these things as well.
The Filco Majestouch is probably the easiest to call "the best". It's sculpted (usually considered a good thing), can be ordered with any Cherry MX keyswitches, has the option of NKRO, you can get a tenkeyless version (no number pad), and has very good construction quality. The Cherry MX switches:
Cherry MX Black - Very stiff, tactile, but non-clicky. If you like a very stiff key this is a good choice, some people like them for gaming, others don't
Cherry MX Blue - Moderate, tactile, clicky. Often considered some of the best typing switches. If you type a lot and don't mind clicky noise this is a good choice.
Cherry MX Brown - Moderate, tactile, non-clicky. Somewhat of a compromise between the Blues and Blacks. Often chosen by gamers who don't like the stiff springs of Blacks, but don't want the clickyness of Blues.
However, sometimes a cheaper board will serve in the Filco's stead. If you want a sculpted keyboard with moderate stiffness keys that are clicky, you could pick up a used IBM Model M keyboard that will work almost/as/better than a Filco with Cherry MX Blues (depending on preference), for just $20-50 instead of $120+.
So it's complicated.