I generally agree with other posters - you won't like the refillable mug coffe at any of the resorts.
Also, You would only need to buy a coffee maker if you are staying at a value resort. I think even Pop is going to start having coffee makers in the rooms, but as of Sept. they didn't. Also the family suites at ASMu have them. Any of the mods or deluxes have coffee makers inthe room. It is probably better to bring your own coffee grounds and filters. In a pinch, I've used two of the packets they provide to make a good strong cup - but the staff isn't always great about restocking the rooms.
They recently redid the QS at the Dolphin, but they had Starbucks before, I can't see that they wouldn't have it now. You can even get a refillable mug! CSR has a coffee bar. POR did not have one the last time I was there, but they have also redone the QS place there, so maybe now hey have one. The Swan also has a coffee bar in the am, but I don't think it was Starbucks. They did have those flavored sryrup shots to add though.
Also, if you have a car, there are several Hess stations on property. Not sure about their coffee, but it's got to be better than the Nescafe.
On the hub in MK - but only in the AM - they have (or at least used to have) coffee bars where you could get espressos, etc.