I've never been big on doing more than one park in a day, myself, although back when all tickets were park hoppers, I did park hop on occasion. Gernerally, when we go to WDW we stay long enough that park hoping isn't nessesary. Because of this, I personally feel that the longer the trip, the less valuable the park hopping option becomes.
For example, our 7 night itinerary usually looks something like this:
Day 1: arrive and check in, no park, just hang at resort
Day 2: MK all day
Day 3 Epcot all day
Day 4: Resort day, spend day at resort pool or other resort activities, DTD in evening
Day 5: MGM
Day 6: AK until mid afternoon, evening at resort
Day 7: Water park until mid afternoon, evening at MK (to say "good-bye"

)
Day 8: Check-out and depart for airport
However, if for some reason we were to take a shorter trip, park hopping would be a move valueable option: For a 5 night stay, our itin may look like this:
Day 1: arrive and check in, no park, just hang at resort
Day 2: MK all day
Day 3: Epcot all day
Day 4: Water Park, DTD in evenng
Day 5: AK until 2, then hop to MGM to close
Day 6: Check-out and depart for airport
Or, a super fun-packed 4 night trip:
Day 1: arrive and check-in, evening at DTD
Day 2: MK
Day 3: Epcot
Day 4: AK until 2 PM, then MGM until close
Day 5: Check-out and depart for airport
In all cases, as you can see the only time we feel it's nessesary to park hop is when we need to free up a day for another activity. We also feel that the best park hop combo is AK to MGM. There are two reasons, one is that AK does not have an evening fireworks show. The second is that both AK and MGM dont' need a full day to tour the park effectivily (although you won't be able to hit every show and attraction in either). In MK and Epcot, there is so much to do that we find a full day dedicated to each park is best. We go at park open, and by the time we get tuckered out, it's time to find a spot for the evening shows (Wishes, Spectro at MK and Illuminations at Epcot). If we park hoped from MK to Epcot, or Epcot to MK, we'd miss an evening show at one or the other.
But, that's just how WE prefer to travel. "We" are just DH and I, no kids. Having kids can change everything, or so I'm told. So, if you can afford the park hop option and feel that you will want to park hop, then go for it. If you really want/need to save money, then it is more than possible to avoid park hopping on all but the shortest of WDW vacations, and you'll still have a great time!