J.S. Bach’s keyboard Partitas, and English and French Suites are full of wonderful possibilities for string ensemble arrangements. I have only gotten to a few of these, but more will be forthcoming. The suites are full of dance-like movements such as bourrées, gavottes, minuets, gigues and sarabandes. A favorite of mine is the Sarabande, from the 5th English Suite, BWV 810.
Here is a link to one of the Sarabande arrangements.