I speak English best. My Spanish and Japanese are marginal at best. I do often feel my Spanish skills have faded since my High School days. However, I do kind of brush up on it a bit watching La Liga (Mexican soccer, or at least the series I've known as Futbol Liga Mexicana) matches from time to time. As for my Japanese, I was never too good with that. I do try to stay up on my Japanese at times.
If I wanted to brush up on languages (which is not the point of this thread), I wouldn't mind trying to learn French, Polish (because of so many Polish friends I have online), Vietnamese, and even Filipino... including Tagalog.