Pentel Energel 0.7mm is the best pen I've ever used, period. Effortless writing with almost no friction. Clear contrasty quick-drying ink. Never too much ink (blotchy) or too little (streaky).

I don't trust the recommendations of this page. They recommend pens as blanket statements not mentioning size, and that's just... wrong. and imprecise. For example, the Pentel Energel 1.0mm is too blotchy. The 0.5mm is too scratchy. The 0.7mm is just right. Also their uniball recommendation is strange. I've tried all kinds of uniball pens and never liked any of them. They seemed to require too much effort, or had ink that wouldn't go down cleanly.