I would second the Got Friends Freeware collection. All fantastically made and a bit unusual:
Also well worth a try is the Scrapyard Monster by Lord Frites:
https://flightsim.to/file/55992/the-scrapyard-monster
Some awesome free Gliders by MADolo:
https://flightsim.to/profile/MADoloSimulations/uploads
And this DG-808S by Touching Cloud is a brilliant, complex, modern and fast Glider:
And this powered Hang Glider too:
This new release of the Extreme Xcub is awesome too, with many available variants and performance upgrades:
You might find some other ideas in my Top Freeware Aircraft topic too. There is a link to a Google Sheet with ranked aircraft as voted by people on the thread. Make sure to check both “tabs” (Scratch Built and Mods):