need specific distro choice help

I want to transition from a bridge graphical interface to full command line reliance and need help choosing the right distro.

Currently, I run Mint 13 (Cinnamon) and, for example, understand the switches in the ls -Falib command and can interpret the output, but I can't run dpkg on the command line without messing up my system. I'm unhappy with Mint because it seems very graphical-interface-oriented. I've had a look at Slackware, Gentoo and Fedora, but I have an AMD processor that might not be suitable for Slackware, Gentoo appears to be having serious kernel bug issues right now, and Fedora could be too restrictive because of its exclusive open-source policy.

Given my overall goal, what distro(s) would you recommend I switch to on a dual boot to try out?

Miki