In Y, for me it's the DL 764 in exit row 30 or the KL 747 in the Economy Comfort mini-cabin with the two-seaters in row 11 - both offer unlimited leg room and good IFE, plus no middle seat. Seated in those seats in both of my upcoming TATL trips
In J, I'd probably go for the same aircraft types given the lie-flat seats on the DL 764 and row 77 on the KL 747 (angled lie-flat seats, but few things beat the upper-deck). Personally I'm not a fan of J on the A380 - feels more like a hostel dorm to me.
Programs: DL PM; TK *G; HHonors Gold; SPG Gold; Points but dirt with everyone else
A380 is nice in Y if you get a seat in the upper deck. Took a wander through the lower deck and decided I would avoid it if I had to sit there. Definitely agree with acjflyer about row 30 on the 764 being a nice ride. The 764s are nice in general, as there are no rows of four seats. The AVOD is also pretty good. (Less of an issue for me now that I have an iPad. I found the AVOD in my exit row seat on the A380 to be really unresponsive. Not sure if that was because of a bad controller or a general problem. Seats with video and tray table in armrest on A380 are much narrower than the equivalent on a DL aircraft.)