I seem to be a sucker for writing implements :-))
Me too... weird...
There's something about a new sharpie that just exudes quality (notice my avatar).
Full size version:
I write constantly at work, it's just notes on what I've done to various computers, but it's constant.
I've been using these Staedtler "Liquid Point 7"s. I haven't tried very many pens, but for what it's worth I'm impressed with these. (I pretty much shopped pens for a good 10 minutes at Staples. I ended up buying these because they had a .3mm tip and "looked fancy." They were about $6 for 4.)
First of all, they're super black, they seem to really lay some ink down. They're not like the Bics that I used to love where the "black" comes out pretty much grey. Every now and then I'll photocopy something I've written; it's actually pretty hard to tell which is the original and which is the copy.
The ink lasts till the end. The reservoir has to be pretty much barren before the writing looks bad.
Lastly the clip is very good. I keep the pen in my shirt pocket, and remove it and replace it constantly. I know it's nerdy, but I can just slide the pen in and out of my pocket without looking. It stays put too, the marker that I keep there slides all over the place, and is pretty annoying, I'm constantly restraightening it. I also have a habbit of sticking the clip onto my finger and taking it off constantly just to hear it snap back into place, the clip doesn't bend or break or loose grip.
On a side note, I ended up washing one of these (and a black Bic sharpie knock-off) in a load of whites. When I took the cap off the Bic marker a little watered down ink came out, but when I took the cap off the pen what looked like pure ink poored out and stained the floor. I think this says something good about the cap.