Mmm, mech keyboards.
I own a Filco Tenkeyless with Cherry MX Blues, a Filco Tenkey with Cherry MX Reds, a Topre Realforce 86U with the varied key weights, another keyboard with Cherry Blacks from Steelseries, and an older Matais with Alps switches of some sort. I also had a Filco Tenkey with Browns at my last job.
Out of the bunch, I bounce back and forth between the Topre and Filco Red, with the red being my main squeeze at the moment. I flip over the Topre from time to time if I'm going to have to do a bunch of typing on membrane keyboards at work as the Topre uses capacitive switches, so it needs a full bottomout unlike the reds which actuate much higher and don't need bottoming out. The Topre shines if you're going to be bottoming out on the keys/have a heavy keystroke or still want something of a membrane-ish feel. It's also pretty quiet, with only a deep and gentle "thunk" sound. If I can get a flow going, then the reds come in to shine since you don't have to bottom out on the keystrokes, and they feel lighter and speedier than the blues or browns while still maintaining tactile response. But if I've been typing on membrane keyboards a lot, then I fumble pretty bad with the reds keyboard as my fingers are too used to banging on keys with all their might.
I don't like the Cherry Black switches at all. They're very, very stiff and it feels like I'm banging away at a membrane keyboard. The blues are fine -- a bit stiff feeling after breaking in but they're loud when I'm in 100 WPM mode. Not as loud as an IBM M or anything, but loud enough that I don't want to use them after my girlfriend goes to sleep in the room next to the office. The Alps in the Matais keyboard are freakishly loud, and feel just like an old Model M. The board probably weighs close to the original xbox, so it makes a wonderful office self defense tool.
Last I heard, reds are exceedingly hard to find nowadays. About the next best thing would be browns. Little louder and more tactile. Topre Realforces hover around rediculous prices and some people don't consider them mechanical keyboards in the traditional sense. I still hold that reds are the best overall, but barring that I'd say go with browns if you're going to get a newer keyboard. Or, you can grab a cherry blue based keyboard from a location (online/retail) with good return policies and give that a shot. I think Best Buy should sell the Razor and Microsoft cherry blue based keyboards, so they might have them on display.