I have "only" about 125. Truth be told, there are maybe five or six that I actually use. The rest are there for reading like novels, or because they looked nice, or I have some connection with the author or place associated with that particular book. Many of the recipes I cook from are either oldie but goodies from my Mom and Great Aunt, or dishes I've created on the spot...and, not writing down the ingredients and measurements, am unable to recreate exactly the same.
I find a lot on the internet, too - cuisines I want to try but am unwilling to invest in a book for until we sample enough dishes. I'm thinking that 125 might be more than I'll keep if we ever clean out the house so we can sell and move back to Ohio. Weight=dollars, and some of the books aren't really worth the $$.