My oldest pens are the Uni Pin pens, I use to use these all the time, they were quite good pens and not too expensive. Haven't used them for a while now as I am playing with newer pens so they are starting to dry out.
This is the Pilot G-TEC-C4, its a gel pen but the lines are nice and thin.
Another Pen I use to use all the time for larger areas of colour is the Paper Mate Flair. It does run out quickly and tends not to survive not being used for a while as its a felt tip
This pen I was given as a present have haven't really used it properly. Pentel Brush Pocket Pen, however I think I might start using it again as I have discovered its more waterproof then most of the pens on this page.
Derwent Graphik line Markers, I bought these pens 2 years ago and fell in love with how dark the black is, and then got the grey to add more depth to line drawings. The sepia and Grey come in 0.1, 0.3 and 0.5 sizes whereas the black has 0.1, 0.2, 0.3, 0.5 and 0.8. Derwent also do a range of paint markers so you can get a white one as well for highlights.
Staedtler Pigment liners, I'll be honest these pens I have used the least amount compared to the rest as they are not as waterproof as I had hoped.
Ooooo I love the Zig Mangaka Flexible pen, it came with April's Scrawlrbox (I think) along with the manga 0.5 (which is a size I don't use often). I already have the replacement pen in my shopping basket on amazon ready for when it finally runs out (Which might be soon as I use it so much). Any pen work in the last few months has had this pen used on it :)
Another Scrawlrbox pen is the Stabilo Point Max. This one is not waterproof at all and limits its use.
Artline 200 again another Scrawlrbox pen and again not waterproof, but when you get it wet it kinda goes blue lol
Stabilo point 88 This months Scrawlrbox pen (August), I already have one of these, it came with 9 other coloured pens that I use for admin stuff with my Etsy shop. They are nice to write with, I've read that they run out quick but I haven't found that.
Micron Pens the newest addition to my collection and I love them so much as they are waterproof so I use them a lot with the Mangaka flexible for a lot of my recent work (skull-a-day)
Anyway it's nice to finally test and compare all the pens against each other.