Although not mentioned before, I use a Cross Century. It's a classic. Has a nice, heavy, balanced feel, lifetime warranty, and looks quite refined.

I too am a lefty. I find the gel ink, although faster drying today, isnt quite fast enough for my left hand when an idea is being captured in the heat of the moment. Thus, I am a ball point fan, regular ink. I use fine point. I never have "bleed through" problem on the moleskin, but there is definitely show through. This is because the ink is very, very black and pure, and since it's a ballpoint, you mash the paper when you write.

But, I thouroughly endorse the Cross Century. My grandfather had one, and bought one for my father, my father bought one for me. It's such a classic pen, that I would bet many of your fathers and grandfathers either bought one, or were given one at some point in their lives.

This topic is much pr0n for me as well, so much so that I registered specifically to comment on this post!