Eavolution

I loved that thing as a kid, I’d completely forgotten about it!'.

I’ve only used Deluge on Windicks but I have to say ktorrent was good while I used it on Arch with KDE.

This won’t be very popular, but something with manual memory management. You probably won’t use it a whole tonne, but that’s not the important thing. The important thing is the understanding of memory concepts such as addressing and pointers.

Personally I learned C++ first, haven’t used it a whole lot, but it absolutely helped me understand other languages much much much better.