As for which park to stay at- When my family visits we always try to stay in park for universal, but don't think the benefits are worth it at Disney. We are currently booked for the Hampton at on Buena Vista at Disney and will be going in less than a month. I'll let you know how it is when I return.
I just got back from a weekend get away at Islands of Adventure and stayed at the Portofino. When you stay on site at Universal you are either within walking distance of the park (5min from Hard Rock or Royal Pacific) or have heavy access to water taxis/shuttle buses or can take the scenic walk that takes about 15 minutes(Portofino). You also get an express pass that takes you to the front of every ride except Harry Potter. Your highest waiting time may be 10 minutes but is usually no more than 2 or 3. If you are a park shopper all of your purchases get sent straight to your hotel same day so you don't have to carry them around for even a minute. If you like to eat in your hotel room Universal's hotels are also conveniently located near a very large Walgreens which has a full stock of milk, sodas, and any foods you need. The money you spend staying on site here just seems very worth it at Universal to me.
I think the only time we ever stayed on park at disney was when I was less than 10 years old. It was very nice for my parents then because we have a family of 6 and transportation was provided. I would say if you are traveling with kids it's worth it to stay on site... Especially if those kids are young enough to need to go back to the hotel room to take naps, or have accidence, etc. If you have older kids or just you and some other adults I say stay at universal and drive to disney. It's not THAT bad of a drive but is a slight inconvenience.
If you'd like to know anything else just ask. I can only speak for myself but I have been attending theme parks my entire life and LOVE them to death. We have tried about everything and have had ALL age groups attend trips with us. (1YEAR-65Years Young!) Large groups (15+), Pets (Small Shih Tzu), on site, off site, 2 days-a full week. We've tried it all I feel.
Port Orleans: French Quarter is very nice option.
The perks at Disney are worth it and they do have a meal plan there as well (in fact, a couple). I think it might be good to know what the ages of your group are and what you want to see and how much you want to spend. There are resorts that are walking distance from the parks, but they tend to be the higher one!
Another good option, especially if you have points with Marriot, Hilton, or something like that is the Swan or Dolphin which is run by one of those (I think, but I know not by Disney)
If you are in the off-peak, I would suggest staying at a Disney resort the entire time. This will is also the time they offer the free dining package (basic level). You can even break up your trip and throw USF into the middle of the week.
Terri- I have recently stayed at Portofino Bay for the first time and loved it. However, I think the hotel rates at Disney would be better than at USF. Although the benefits are great at USF. I'm not sure of how many days we would be visiting USF yet if we definitely go to Orlando.
Anthony- I love Port Orleans French Quarter( And Riverside!) They are some of my favorite. The group will be 4-5 people. Two teenagers and then 2-3 adults (40's - 50's) who are wiling to do what the teenagers want (wether they want to visit a certain park or ride certain rides.) None of us are too picky on hotels as long as they are clean and have a reasonable price that is within our budget. The hotel room doesn't need to be over $200, so for Disney that eliminates all the ones surrounding Magic Kingdom area, and although that would be nice, its not that big of a deal if we stay in another resort area. Oh but on the hotel's the All Star resorts and Pop Century, are not an option.
M. Ryan- I'm not sure exactly when we are going (if we even are going) seeing as this is an option but we are leaning towards it. I doubt we would do the dining plan though, if we do go.
Walt Disney World's Magic Kingdom
Disney's Animal Kingdom
Disney's Hollywood Studios
Disney California Adventure
Universal's Islands of Adventure
Universal Studios Florida
Universal Studios Hollywood