A pretty good list.
The Perfect Circle: Hiking the Annapurna Circuit
Chile’s Torres del Paine Circuit
Compare that line-up with our own top 10.
I’m headed for the GR20 myself this summer. Independently.
Europe’s toughest trek. That’s the reputation of the GR 20–the relentlessly rugged Grand Randonnée (Great Walk) that traverses 112 miles across Corsica, a Mediterranean island off the southern coast of France. This roller coaster of uneven pink granite will make you sweat, scramble, and curse as you grunt up 35,000 total vertical feet. …
Or go guided with Tour Aventure (tour-aventure.com), the only trekking company in Corsica with English-speaking guides. No permits required.
besthike.com 
I agree; a pretty good list.
For those of us who are annoyingly picky, “Classic” means something different than “Best”. For example, the Milford Track is definitely classic, but there’s probably 5 tracks in Aus/NZ I’d do again before Milford (including #’s 3 & 10 on your List).
Have fun on the GR20! If possible, get there soon – will get hot and crowded. FWIW, Kilian set the record 2 years ago at just under 34 hours (with full support from Solomon).
GR20 – Another great challenge and adventure for you Rick!
It will be fun.
DSD