So having seen multiple productions of every Sondheim show, both live and recorded, and knowing most of them by heart, I tried to accomplish the impossible and rank every single one of his stage musicals (aside from The Frogs, which I haven't seen). I am aware that some of the placements will be fairly controversial, but this is mainly just a jumping off point for discussion around the various shows and not a serious matter.
The list goes:
18 - Do I hear a Waltz?
17 - Saturday Night
16 - Anyone Can Whistle
15 - Road Show
14 - West Side Story
13 - Funny Thing Happened On The Way To The Forum
12 - Company
11 - Passion
10 - A Little Night Music
9 - Into The Woods
8 - Merrily We Roll Along
7 - Gypsy
6 - Assassins
5 - Follies
4 - Here We Are
3 - Sweeney Todd
2 - Pacific Overtures
1 - Sunday In The Park with George