I'm an ex-Orlando resident and former annual pass holder to Disney, Universal and SeaWorld, so take this for what it's worth.
I would rate the parks in this order: Universal Islands of Adventure, SeaWorld, Universal Studios, Epcot, Magic Kingdom, Animal Kingdom, MGM. Admission is now on the order of $75 per person, and $35 more if you buy an express pass at Universal, which I highly recommend. Wait times drop from 1 hour + to about 3 minutes, even on the more popular rides. That gives you a chance to actually enjoy it instead of waiting in line all day. Disney has fast pass for free, but it's limited in that you can only fast pass one ride at a time and then you get a window of opportunity later in the day. Better than nothing, but only slightly.
The first thing you should do when you get into the park -- especially a Disney park -- is make dinner reservations, unless you're planning a walking junk food dinner. Otherwise you will face a 90 minute wait to eat.
For hotel, if you are renting a car stay off Disney property. The Disney hotels are very overpriced for what you get. If you're planning to use Disney transit (including to/from the airport) and don't need a car, the rental car savings might offset the Disney hotel premium. If you do stay off-site, be advised some of the nearby neighborhoods in Kissimmee are, uh, not-quite-scary-but-almost. Choose wisely.
On the "deals" for tickets, beware the brokers that want to sell you "two unused days" from someone else's 5 day pass. The parks use biometrics that tie the ticket to an individual. The off-site ticket brokers will not save you more than a couple dollars. But they will save you the 30 min to 1 hour wait in the ticket line, so they're useful from that respect.
All told, expect to spend $150 per person per day at the parks. Food and drink prices are VERY high, in addition to the admission. For kids, maybe $130.