In your opinion, what metro station is worth visiting for it's own sake - unique art work; interesting architecture; view upon exiting; intriguing history... etc!

excellent question i've been thinking about myself and eagerly await opinions.

the Louvre station comes to mind with re-creations or perhaps actual artifacts in windows on the walls as i remember.

Arts et Métiers (Line 11 platforms). Submarine station.

Louvre Rivoli is pretty for all the object casts (they aren't real) on display at the platform. Maubert Mutualite has fun light panels arching over the track but I wouldn't say that (or really any) station is worth visiting for its own sake, per se.

Concorde. It is so much fun to bring to read the déclaration des droits de l'homme on the white subway titles.

Context - When we backpacked through Europe (20 years ago!) met some Australlians who had a game they had played on Metro/subway systems throughout the world. Randomly select and get to a station; get out; walk until you find a place to buy a beer; return to the subway; randomly select another station; repeat. We did it in London, and ended up visiting places we never would have.
I am thinking about ways to modifiy this for our trip with the kids to Paris next year, and my one thought was to make it semi-random, or to at least give more interesting stations have a higher chance of being chosen.

Arts & Métiers -- Jules Verne ambience
Palais Royal -- glass ball canopy exit
Europe -- video reports of European event
Gare de Lyon, line 14 -- tropical garden

Bookmarking...excellent post. Very interesting. I am taking notes.