I'm bilingual fluently, and I know another mother language that only very few know. I took Deutsch when I was at high school (and almost went to school there), but "Ich liebe dich" is probably the only thing I could remember now ...
One of those things I want to do before I die is mastering another language (yes, Deutsch of course).
Bobby, if you are in the US, Spanish is probably your best bet, since there are a lot of Spanish speaking ppl here. US have a lot of economy trade with spanish-speaking countries too (a lot of jobs require Spanish-English bilingual ability). But of course any other language that our country has business interests with is good and not to waste to learn.