Limited edition or hand made pens for me.

My grail was a V HS London Fog which I started lusting over when I started the hobby. I picked one up late last year after picking on up.

That being said, 'grail' as a definition or standard is very different from person to person; a loose definition vs a strict definition.

Some people consider a grail pen to be their next pen, others a good 'common' expensive pen (Lamy 2k, Pilot Custom 823, Metal Falcon, sailor pro gear, king of pen, 3776), while others state that a grail is something that is rare, exquisite, numbered, something like a London Fog, an Arco Celluloid, (numbered) hand made pens (like Pilots 100th Anniversary). I subscribe to the later of the 3 definitions, the strictest definition.