Les Indes Galantes is wonderful, although I have only heard the suite version, no singing (Orchestra of the 18th Century, Frans Brüggen conducting, on Decca). In general, Rameau is an excellent composer, his solo harpsichord works are among my favorites (as played by Blandine Rannou on Zig Zag releases: https://play.spotify.com/album/3XkblzycqTXtAn95DBQr2X).
Another somewhat obscure baroque composer is Alessandro Marcello. I enjoy his concertos for oboe (for one and for two), as presented on this Arts Music disc: http://artsmusic.de/Concerto_in_D_minor_-_Unpublished_Concertos_and_Cantatas/topic/redline/shop_art_id/166/tpl/artsmusic_article_detail
Marcello's style is similar to Vivaldi's although I prefer Marcello. He sounds less show-offish for me.