What makes a record collection "great"?

Many times over the years I've heard people describe someone as owning a "great" record collection. I own well over a 1000 LP's, many of which I would call great music, but no one has ever complimented me on having a great collection.

What differentiates a good or very good collection from a great one? Is it size, collectability/rareness, genre, original pressings vs. reissues, all, some or none of the above? I look forward to your input.