I would say Egypt in 2007, before the looting of the Museums.
Perfect trip, in November so Temperature was about 23 degrees Celsius, felucca up the Nile, then cruise up the Nile, Abu Simbel, Hot Air Balloon over the Valley of the Kings, Donkey ride into The Valley of The Kings, Camel ride through a village, seeing Tutankhamen going inside the second Pyramid, and generally a great group of Australian, English, American, Irish, New Zealand people.
Second would be my US 2010 trip Fall Foilage in New England, Boston to Maine, New York, Philadelphia, WDC, then the South.
Now I am planning my next trip for next February and March which is self driving from
New Orleans through Alabama, Florida, Georgia, South Carolina, back to Georgia, Mississippi then Louisiana ending in New Orleans, so I am hoping this one becomes the best.
Look forward to doing a West Coast USA trip so love reading about your trips.
I will dream of Summer while I am cold in 6 degrees Celsius at the moment.