I think it really depends on how you want to tour the parks. As GADisneyDad14 stated, if you want to go to MK first, I would start at GF. I would probably do AK from there as well as, with either resort, you will need to take a bus to AK. Once you get to RIV, you can then just focus on DHS and EP.
We've stayed at both (GF, VGF and RIV) and, IMHO, as an overall resort, VGF/GF wins. The rooms at VGF are the nicest on property, IMHO. The view from the resort is amazing and you have a ton of restaurant choices, not to mention the monorail and the upcoming walking path to MK. RIVs rooms come in a close second to VGF's - fantastic layout, very comfortable and well-appointed. RIV felt a little isolated, though (even with the Skyliner) and there aren't as many dining choices unless you want to walk to CBR or take the Skyliner to the EP resort area. There is definitely no right or wrong way to order the resorts for your trip. I would definitely consider your touring plan and what kind of atmosphere you would like to start and end your trip with.