Mine is;

1) Stoney Littleton long barrow

http://www.themodernantiquarian.com/site/51/stoney_littleton.html

2) East Kennett long barrow

http://www.themodernantiquarian.com/site/302/east_kennett_longbarrow.html

3) Stanton Drew Circles

http://www.themodernantiquarian.com/site/4082/great_circle_north_east_circle_and_avenues.html