Anaheim Plaza is clean and nice and had a fridge in the room. Not amazing, but good for the price. Right across the street, so it's a short walk. I haven't stayed at Desert Inn, so I am not sure how they compare.
We stayed there last August and it was ok. I would be willing to do it again if the price was right. The walk seemed long after the first 2 days. We did it 3 times each day plus a ton of walking in the parks so our feet were really hating us. That extra distance was worth $30 a night though. It's basic but decent. What would possibly sway me more than the distance is the fact they don't do a free continental breakfast. If you like continental breakfasts and would fill up on it you might be better off staying at the Desert Inn. (I have no clue how good their breakfast is.) We spent $20 to $25 each morning at Denny's for breakfast. Although it was nice and filling it added up. Probably would have been cheaper to eat at Disneyland.