OK. Digitech RP-250, their website has lots of info.

http://www.digitech.com/soundcomm/gu...?productid=226

Here's what I like about it.
Amp models. 5 Fenders,4 Marshalls,2 Vox, 1 HiWatt, 2 Mesa's, 1Matchless, 5Digitech(their own models of modelers), dreadnaught acoustic sim, and direct (no amp). Do they sound just like the real thing? Nope. Can they be tweaked to get close? I think so, I haven't heard all these amps side by side comparison-wise.
Dist.. 13models, ts-9,ts-808,Guyatone,Rat,MXR,Boss,ArbiterFuzzFace,BigMuff, more
I'm not gonna go into every model of every effect, it's too long a list. Suffice it to say there's plenty of tweaking possible, and neccesary, IMO. But spend some time doing the tweaks, and there's some awesome tone in there, I promise.
Cab. simulations, EQ, all the standard effects, wah models, and more.
Built in tuner, 60 drum patterns, plus metronome, and USB to computer.
The expression pedal can be linked to almost any 1 parameter of any effect. I enjoy being able to adjust speed, or depth, or pan of tremelo, dist, phaser, reverb, gain, volume on amps, you name it, it's a nice feature. Plus it doubles as a wah, stomp down on the toe, it's the wah you choose (Crybaby, Clyde,etc), stomp again, back to expression parameter you set.
I believe the X-Edit feature is my favorite, and I didn't think I'd use it!
Download the free drivers, hook it up USB, and tweak presets quick and easy, then save 'em to your computer, the choice is yours to load them onto the unit or not. I think the RP-250 section of the online sound community has about 150 user patches so far. I've downloaded most of them, I found a few I liked. You can preview them by running them through the unit and listening to them, if you like them you go to "device" and "store". Otherwise leave 'em on your computer to tweak another day.
I think I'm getting some really good sounds out of this unit, but it took some tweaking, and the X-Edit is lots easier than knob twisting, plus it offers more flexibility (more EQ'ing, etc) than the knobs alone. Without it you're only getting about 75% of what the unit can do.
And it's $150.

Here's what I don't like
Digitech Whammy...doesn't track smooth, if you're "whammying" (is that a word?) up or down an octave, it "warbles", unless you sweep the pedal fast
Bass sim...same thing, more than one note at a time and the "bass" sound becomes a "BwAAhhWHATthefnote do you want from me????" sound.
The 60 user presets that can be edited are clones of the next factory 60 that can't be edited, and about 40 of them are sh*t, IMO. So you get about 20 good presets right outta the box, and 40 more you can make good, and 20 more factory that are good, and 40 you can't do a damn thing with. I guess 60 good user presets are plenty, I haven't got that many tweaked yet, but still it's a waste of 40, IMO.
And finally, lest anyone think I'm pushing anybody else to buy Digitech....and to answer Tone's original post.
This IS what I use.
I don't think it's the best. There are modelers out there that cost 10X as much. There's a reason why.
I do think it's the best bang for the buck, and was available in my part of the world when I wanted one. Ever have the GAS so bad you can't wait 5 days for UPS to show up? I have.

Seriously, there are many fine modelers out there nowadays in all price ranges. And there's no reason to limit yourself. Buy what you like today, and tomorrow go compare and buy something else. I've got four amphs and love 'em all. Why should modeling amphs be any different?