To me, the greatest collector is the one who only collects those games which he likes to play. I do not appreciate some other collectors, for example:

The Collector who only Collects Rares. These people often fail to figure out why many games are rare, because they suck.

The Collector who only Collects, never plays. Unless you have a love of artwork, why bother? Go collect something else.

The Investor, buying low and selling high. These are the parasites of the world.

The Collector who must have 3 of everything. Nothing is eternal.

The Unorganized Collector. No wonder why he spent money on something he already owns. Unorganized shelves are unsightly.

The Hoarder of the Unavailable. This fellow will keep his prototypes to himself , keeping them from being dumped and enjoyed by others.