I've stayed in most of the hotels on what I call "offsite row" (sure, it's on "Disney property", but the only thing Disney about it is that it's within walking distance to DTD)
For most of those properties, price is the main attraction. If you're paying rack rate at any of those places, you've been fleeced. They're always running specials, and you can always find a deeply discounted rate on Expedia, or through triple
AAA, or even by calling the hotel and finagling the reservations staff.
Disney doesn't bargain like that. A lot of you seem to really be into the "Disney touch", but I'll confess that I don't really get that much of a charge out of staying onsite unless it's in one of their top-end or home-away-from-home resorts. The All-Star places have frightfully small rooms and little else to offer, while the moderate resorts don't do much for me either (with a few exceptions; I really like the atmosphere at Port Orleans, for example.)
The Downtown Disney hotels run the gamut. The Wyndham Palace (or whatever it's called now) is a beautiful property, with a great pool area, balconies in the rooms, and an awesome lobby area -- love the lobby bar --. That's the class in the neighborhood, by far, but you'll likely pay for it. Also, if you're not into staying with a bunch of conventioneers, steer away from that place. It's geared toward big meetings, etc.
The Hilton is nice; there's a good Benihanas in there. The Best Western I think is the big round hotel. It's configured a little strangely, because they shoved all the common areas (lobby, check in, restaurant) into the cylindrical shape on the first few floors, so it's a tight squeeze in the public areas. The rooms are good though, because you get a balcony, and if you're up high enough you'll have a great view.
The Doubletree boasts "suites", in that you get a separate bedroom. Beware, though. The rooms are divided by slatted folding closet-type doors. If you want to have real privacy between the people sleeping in the bedroom as opposed to the pull-out in the living area, you won't have it. You can carry on a conversation between the rooms with the doors closed without even raising your voice.
I've heard a lot of people slagging the Royal Plaza, and I'm not sure why. I kind of like that property, in that it's not part of a chain, and the service is usually friendly. It has a nice lobby and a big pool area, a bar and restaurant. Nothing special about it, but it's comfortable. The rooms are interesting. If you stay in the tower, you get a "balcony", but it's really just a slider you can open onto a really small ledge. You really can't sit out there, but you can stand against the railing. The tower rooms are bigger than a standard hotel room because there's a small divider near the window, that separates the bed area from a cozy recliner that pulls out into a single bed. Perfect room for parents with one child. The bathrooms are nice, too. They're big and actually have some marble. You can also stay in one of the cabana rooms around the pool area. I haven't been in one, but I hear they're popular with the younger crowd, because most of them open directly onto the pool deck. Noisy, but fun.
I haven't stayed at the Grosvenor. Something about that name smacks of a stuffy big-city downtown type of joint . . . I can't speak to that property.
I think there may be one or two others on that road, but I can't recall them at present. In summary, I think you can find comparable quality to a Disney resort for less money (if a moderate Disney resort costs @$150, you can get approximately the same quality of accommodation for $80-$90 on offsite row), and the fact that the hotels are in walking distance of DTD make them more attractive to some, but certainly you give up a bit as against the "Disney touch".
The Hilton seems to be the nicest. Never stayed there. The prices are a bit high. But, all of those hotels on Hotel Plaza Blvd. are nice.
I want my full Disney experience 
Staying in DTD, we can walk back to the hotel (although probably with a bunch of drunk strangers around *L*) 
