I don’t spend a lot of time using a P2P application but when I do, the latest one I’ve used is Limewire

This page reviews various P2P apps looking at how much bundle-ware and EULA payload each program contains. The study was commissioned by Limewire.

LimeWire has no EULA and no bundle-ware. If you already have the Java Runtime
Environment installed, it also has the smallest install footprint of any of the
apps (cuz it’s a Java application).