Wasn't Telemann clever? He wrote so much music for so many instrumental combinations. Here's his Canonic Duos in:
Note that you can play the above with instruments reading the same clef or a different clef; they are written in the same key! (therefore violin & viola, viola & cello, or violin & cello work). These were typeset by Johan Tufvesson.
Here's the first of Telemann's Sonatas for two violins/flutes from Mutopia:
Here's two Hotteterre sonatas for two flutes without continuo (but I'm sure they would sound delicious on violin too!)
Sonata 1 - score
Sonata 2 - score