I just got A+ certified

I know you'll all scoff and regard me as a scrub, but I'm making /prog/ress towards achieving Satori. It's not much, but it's a start.

I've messed around with Ruby before, but what language would be good to take up seriously and learn in-depth? The most I've done with Ruby is make some shitty text-based games.

I'm not sure if this will impact your suggested language for me to learn, but I'm currently enrolled in CIS introduction classes for next semester, planning on getting into database administration later on. However, I want to learn how to program as a hobby.

I know I'll have to learn SQL some time in the near future, but I'm wondering if there's anything else I should take up.

In before elitist sages, conflicting suggestions, and inane comments.

Disregard the Ruby hate. People hate the freak show that is the Rails community, and the horrible performance of 1.8.
The language itself is fine. Switching to python would only be an upgrade if you hate Ruby or need to use software that works better in the Python world.

You'll need a working knowledge of C no matter what you do.

You'll want to understand lisp eventually, most dialects are fine since you can't use lisp to make things in real life.
SICP is a great book, but it's not for people who need any sort of hand-holding. Advising you to read it immediately would just be memetic /prog/rider machismo.

Do not learn C++ or Java as a hobbyist. Never use them unless you get paid to do so.

Don't pick up 50 different languages and call yourself an EXPERT PROGRAMMER. Specialize in one, understand in excruciating detail. Once you do that, switching languages will become a very trivial matter.

Join a small open-source project led by knowledgeable and friendly people.

Start preparing right now you career move towards a more interesting path.