In terms of seating/comfort I prefer in this order
KL or AF 787
DL A330 or AF 777 with BEST SEATING (1-2-1 configuration)
DL A350 or refurb 777
KL 747 (+1 if can get 1A, 4A, or 4E, the only single seats on the plane)
KL 777/A330
DL 767 (+1 if can get bulkhead, which has extra room in the area for your feet)
DL 777 non return, all should be refurb by EOY
AF 777 with 2-2-2 config (non-BEST) or A380