My current pen of choice is a TWSBI diamond 580al. It’s great, the cap screws on so doesn’t go rattly and is airtight so the nib doesn’t dry out. The reservoir is huge and lasts a few days. I write a lot at work.
My pilot capless usually is the favourite but I dropped it again and need to buy a new nib. Ouch.
The lamy studio is relegated to spare as the lid went slack and doesn’t stay on.
There’s a kaweco sport somewhere which is a really nice compact pen but it doesn’t have the optional clip so isn’t getting used.
I’m not brave enough to buy anything more expensive, it might get dropped or lost as I don’t work at a desk.