i am a very picky pen user. i have my favorite pens that i use and they are my tried and true marking makers. isn't everyone particular about their pens?
the precise v5 extra fine: my all time, all time fav. i have them in every color. my hand writing always turns out the best and clearest with this pen for some reason..maybe i just strive to make it look good when the pen is so good! warning and only downside: if you're sort of rough with your bag, i often find that the pen can get banged up a bunch and bleed on you when you remove the cap. blech.
stabilo pens: when hannah was living in france, she bought me a set and i love them! i always have such fun when i write and draw with them and they come in a great range of bright and mild colors.
lepen markers: martha says she keeps them in every color by every phone. they're cheap (less than $2/pen) and if martha loves them, i love them.