French, now... there's a language! I struggle and stumble, but some of the expressions just make me smile every time I hear/read them. For example:
Il pleut comme une vache qui pisse (It's raining like a pissing cow) - You just don't get that in English, ya know? Much better descriptor than "raining cats and dogs."
Heureux comme un poisson dans l'eau/comme un oiseau dans l'air (Happy like a fish in water/like a bird in the air) - I guess I just never saw what was so happy about clams. This works so much better for me.
La vie me sourit (life is smiling at me) - What a lovely way to say that all is going well for you! This is exactly how I feel on good days.
Avoir le coeur gros (to have a large heart) - And this is exactly how I feel on bad days. It means "to be sad, real sad" and that's just how I feel... like everything's all stored up in my heart and it's gotten too big and it might burst. I know that we say things like "with a heavy heart" which is sort of the same but, I don't know, for me the feeling is more volume than mass.
Loin des yeux, loin du coeur (far from eyes, far from heart) - Equivalent to our "out of sight, out of mind" but just so much more poetic. Heart > mind. Oh snap, mind.
And, a personal favourite of mine: Peigner la girafe (paint the giraffe) - It means you're doing useless work. I don't know, it just makes me so happy to think that painting a giraffe is considered the epitome of uselessness. Also the image makes me laugh every time. :)