Am travelling to Paris with my 2 teenage daughters (1st time) where should we stay? Marais or St. Germaine?

It's hardly a poor choice one way of another. But we stayed in Le Marais area last week. The 3 teens we traveled with loved it there. It's so close to the Pompidou Center where they go in for free (under 18) and spent a lot of time there. (They were bored with the Louvre.)

The scene is on the alternative lifestyle in the Marais area though, be forwarned. But nothing worse than what you could see in CAstro Street of SFO. It's quite tame, but clearly, the bars are gay friendly, thus, teen girls were safe from ogling of the hets. ;-)

I agree - they are equally nice and equally convenient areas. Both neighborhoods are suitable for teens as well. I might prefer St. Germaine but it costs a little more.

What exactly are you looking for?

The Marais is much better, IMO. St. Germain is fun for looking at Botox disasters.

" botox disasters" we are talking about the Marais or St Germain, not Los Angeles or Miami,..

All teenagers are not created equal, but I'd vote for the Marais.
Also suggest you not confine yourself to the strictly-defined Maria, but also look in he area east of Place Bastille toward Gare de Lyon. It's the edge of the 12th and we have come to like the area.