I use both the DigiTech Bad Monkey and Tone Driver pedals with all of my amps, and achieve fantastic results. Both are very solid, well-engineered pedals that do what they say they do. As DVM mentioned, they work well in a variety of situations, and with all kinds of amps - solid-state, tube, and hybrid amps like the Vox Valvetronix series. The thing I like most about them is their versatility - as in the adjustment parameters of each pedal allows you to dial in just the right amount of whatever you need - - without going into the Twilight Zone as far as tone is concerned.
The Tonebone is indeed a step to "the other side" of the spectrum, but again, its controls allow for acute adjustment, and you can pretty much run whatever you want in conjunction with it, and usually come up with excellent results.
One thing no one has mentioned is the point of "overdrive" vs. "distortion". I think this is important to understand, as the innate characteristics of each will produce different tonal effects. The Bad Monkey being an "overdrive" pedal will push the front end signal of the amp into its natural distortion characteristics. Conversely, a distortion pedal will add that effect on the front end (i.e. the distortion point), and as you increase the volume, there will be a point where that tone will stop sounding good (i.e. muddy, fuzzy). Combining these pedals with different amps, of course, will have different effects. The thing you need to realize is that there are really no rules; yet having a good idea of what each will do will certainly allow you to experiment, and ultimately, achieve success with your tone. The other thing you should be cognizant of is the characteristics of the amp models you are modifying. For example, the Tweed model will respond differently to the overdrive vs. the Marshall model (since its design allows for more gain / saturation at an earlier point in the signal chain) . . . and so forth. Adding the guitar / pick-up equation will also produce different effects with different pedals, and that shouldn't be a newsflash to anyone here either.
The bottom line is this: you can push sound any number of ways with effects pedals, and there is really no best way to go about doing it. Knowing what your amp and pedals will do is probably the most important thing, as all of our ears hear different things, and ultimately, what sounds good to me might not sound good to you.
DigiTech pedals are easily some of the best out there, and I'd recommend them to anyone in a heartbeat. In case it hasn't been mentioned, here is the link to their site. I believe most of the pedals there have sound clips, and all of them are pretty good in giving you an idea of what they'll sound like.
http://www.digitech.com/
Personally speaking, I'd recommend that you explore some of the lower cost pedals before taking the "dive" into something like the Tonebone, or even the Ibanez TS-9. You might even want to check out the Marshall Bluesbreaker II, which I've found to be another great pedal (*sound clips are under the "Downloads" section).
http://www.marshallamps.com/product.asp?productId=62
Good luck!
