The best ballpoints I've ever used (and what I use day to day) are space pens. They don't dry up, they don't break, ink lasts for ages (like the 1 in 100 biro that doesn't get an airlock) and write on anything.
The only problem is people steal them thinking they're not a £20 pen. Having to explain to someone why you're really annoyed with them for nicking what is essentially is a biro means diligent pen pocketing, locking of drawers etc.
You can almost guarantee if someone "borrows" it, they're so nice to write with they'll steal it. And then deny it.