If we just count WDW then my favourite trip was my first in 1988 with my parents. I didn't have any control over it, my dad organised it all, and had done well and found out about some things few Brits knew about back then like the Guided Tours and the Character Breakfast (at what is now Fultons). I hadn't had to pay for it and like my dad loved the attention to detail and the theming. I am not sure what the tour was back then but I remember being told about the utilidors and loved all the little details like the cowboy shoot out that just started while you were walking through Frontierland and Donald & Mickey waterskiiing behind the ferry from TTC to MK.
If we include DLP in our favourite Disney trips then it would have to be March 2013 for my husband's 40th, we went for a full week and just took our time and enjoyed soaking it up rather than rushing from ride to ride and we managed to see and do several things that we hadn't managed to fit in our earlier 10 trips! Our youngest was also at an age where she really started to enjoy being in the parks and recognising her favourites as we went past. My dad and his wife joined us for the last few days, the children didn't know and wrere really excited to see their Grandad and Pauline and take them to their favourite rides/shows.
I don't think for a minute that WDW is perfect, nor is DLP, but if you have a little magic and pixie dust in your heart and see the big picture a few broken lamps or attractions temporarily out of order spoil my trip. Besides most temporary ride closures are caused by guests not actual breakdowns!