Just in case you haven't seen it yet, I wanted to point you to the SMFSD. They have done God's work with early Middletown genealogy, thanks in no small part to Middletown being home to the Godfrey Memorial Library, one of the nation's most important genealogy-specific libraries.
The "official" list of First Settlers of Middletown -- they're always called that -- is at http://www.rootsweb.ancestry.com/~ctsmfsd/Index.html. I just did a lot of work on George Hubbard, of Hartford and added him to the project. (I realize his display name might be confusing, but it's what he's always known as -- except in Middletown, of course. :))
Also, here's the list of the very first families to arrive. They settled in 1650, with the majority coming from up the road in Hartford.
Thomas Allen and Unknown Wife
Nathaniel Bacon and Ann (Miller) Bacon
William Blumfield and Sarah (unknown surname) Blomfield
William Cornwell and Mary (unknown surname) Cornwell
John Hall
John Hall, Jr. and Ann (Wilcox) Hall
Richard Hall and Mary (Anthony) Hall
Samuel Hall and Elizabeth (Cooke) Hall
Giles Hamlin and Hester/Esther (Crow) Hamlin
William Harris and Edith (unknown surname) Harris
George Hubbard and Elizabeth (Watts) Hubbard
John Martin and Unknown Wife
Thomas Miller and Isabella (unknown surname) Miller
John Savage and Elizabeth (Dubbin) Savage
William Smith and Elizabeth (Stanley) Smith
Samuel Stocking and Bethia (Hopkins) Stocking
Robert Webster and Susanna (Treat) Webster
Thomas Wetmore and Sarah (Hall) Wetmore
Nathaniel White and Elizabeth (unknown surname) White