Hi Tom ,
Wow what a grand & expansive topic !!
I fear the shear overwhelming nature of the topic is probably what has slowed any respose to the thread.

Ok let me have a go at it.
The fact of the matter is the boundries keep changing. Once a "grail" item is achieved it is adored, worn, photoed, discussed & admired. The actual pleasure of owning the piece never actually deminishes but the hunting instinct which has been so honed & focussed doesn't remain satisfied for long. Then the trawling of net begins again & finally you become fixated upon the aquisition of another watch.
This is how it was for me, up until last year anyway. I bought my first Heuer in the 1990's but didn't consider myself a collector until 2004/5 when i became a little more computer savy ( it may be better to describe those skills as email & google capable ).
Then the delights of eBay made for accessability & availability of other watches. Discovering the forum was a great thrill & for roughly 2 years i was a a non-contributor, reading only & not coming forward. Then i started seeing threads discussing watches i had either won or bid upon on ebay being discussed by the forum members , this shook me into the reality that i should also come forward & be known on the forum.

Why the lengthy introduction to this topic, well i wanted to show you how i have developed as an enthusiast & collector.
I started in 2005 with the notion it might be nice to have an example each of all the Cal.12 models ( ie 1 Autavia, 1 Carrera etc.) & i was content adding these model watches & thought finishing the lineup would finish my collection - WRONG !!!
I started to understend the significance, rarity & beauty of certain models.
So with this background i will offer up a pictorial time sequence of the watches i desired & placed in the grail catagory but later recognised that the grail label should be used far more cautiously.

Now all of the above are great watches & highly desirable in there own right but to be honest with you i didn't really grasp the concept of a "grail watch" until my search for a Chronomatic began.
I could not locate one, let alone shake one out of someones collection. The mythical qualities of this rarely seen beast made it all the more important once i found an opportunity, i had to go for it - to make a long story short my delight in finally landing the Chronomatic.
Here we have my pride and joy - my paintless wonder.

It kept me in check for quite some time, satified that this watch would never be sold & will always be loved.
But over the next couple of years another feeling woke inside me, yes i too felt captivated by the simplicity & functionality of the 1960's screw back Autavia's. The seed had been planted and so the search began for a dauphine hand wonder. Now as we all know these dont just pop up on the radar everyday, they are unbelievably rare so any and all efforts were focussed on tracking one down.
Long story short its now the 3 register variants of the dauphine hand Autavia's which bring me the biggest smile. They feel simple & honest on the wrist & you have that proud "origin of the species", thought every time you hold one.
So as my all time grail watch ( after having tried quite a few of the exotic Heuer's ) i would say my grail seach has ended & i feel satisfied with these 2446's as my dream watches.

Cheers - Darren