I have a Filco Majestouch tenkeyless with brown cherry switches. I love it.
There are a bunch of good mechanical keyboards out there with a variety of switches.
geekhack.org is good place to learn about them, in particular, this page:
http://geekhack.org/showwiki.php?tit...sary+and+Links
Not all mechanical switches are loud by the way!
http://geekhack.org/attachment.php?a...6&d=1309959583
http://www.youtube.com/watch?v=RYK03...eature=related
Rubber does is what most cheap keyboards (including your old one) use. Scissor switches is what laptops (and some desktop) keyboards use. Buckling springs are the old IBM Model M switches.
I personally prefer tenkeyless keyboards since I consider them to be more ergonomic. With a normal keyboard you typically don't have the typing area of the keyboard right in front of you, on the right is the "arrowkey/INS,DEL,etc" block and the numpad. And to add to that, most people have the mouse on right too.
So usually the keyboard gets moves to the left, since 95%+ of the typing is done with the "typing area", this is not a good thing...
I'm not too sure about mechanical split keyboards ... geekhack has a list of various models...