My favourite is Artline Flow. Omg it feels so good and it has pretty colours!
I have a white one and a black one. The black one has red, blue, black, and green....and the white one has pink, purple, light blue, and light green. I use the white one way more, it's so much more fun ha ha.
They're both perfect though, they glide so nicely...never had issues with sandy ink or scratching. Never cramped up from it. Never had issues with sweaty or slippery hands, or calluses/blisters (the grip is awesome). Never any issues with ink smudging either, though I don't write with my left hand or wipe the page, some pens will leave a clump on your page and just ruin everything.
It's basically the pen I've been waiting for for my entire life.