There are 7 varieties of double daylilies with slideshows below.  My two favorites are Susan Pritchard Petit and Candlelight Dinner.  Both produce two or three huge scapes with 8 to 10 flowers per scape.  My wife loves Lacy Doily, but the blooms are very small & it just doesn't seem to produce many scapes or flowers ... at least here in Houston.

Susan Pritchard Petit
Candlelight Dinner ... rebloomed Aug 8 - 20
Lacy Doily
Night Embers
Frances Joiner
Siloam Double Classic
Double Orange (unknown name)

Susan Pritchard Petit - 5 plants, 6 inch double flowers, 20 inches tall, strong scape with many blooms, 2 are new plants from Gilbert Wild which have smaller blooms in year 1, larger blooms come from Breck's - should have bigger blooms next year, midseason, semi-evergreen, bloomed Apr 18 to Jun 4, 20 days with blooms, Breck's & Gilbert Wild

Candlelight Dinner - 1 plant, 6 inch double flowers, 26 inches tall, early midseason, dormant, 3 huge scapes with many buds, wish I had many more, first bloomed May 15 to Aug 20, rebloomed, 27 days with blooms, Breck's

Lacy Doily - 8 plants, 3.5 inch flowers, 20 inches tall, midseason, evergreen, bloomed May 29 to Jun 20, 7 days with blooms, not a great year, 2 existing plants do look healthy, 6 new ones did not bloom, Sob! K.van Bourgondien

Night Embers - 1 plant, 5 inch flowers, 30 inches tall, early midseason, semi-evergreen, double blooms slow to open but last late into the evening, bloomed May 7 to May 26, 9 days with blooms, Breck's

Frances Joiner - 2 plants, 5.5 inch flowers, 24 inches tall, midseason, dormant, first year, planted Mar 6, bloomed May 21 to May 22, only 2 days with blooms, Gilbert Wild

Siloam Double Classic - 2 plants, 5 inch flowers, 16 inches tall, early midseason, dormant,  first year, planted Mar 6, bloomed - May 6 to May 18, only 4 days with blooms, Gilbert Wild

Double Orange - 1 plant, unknown variety, first bloom to open on scapes tends to zap all the strength of the other bud which fall off, very pretty flowers, bloomed Jun 19 to Jul 5, 4 days with blooms, gift from a friend