If you are using Bitcoin Core then you already have more than 100 bitcoin addresses. You just aren't aware of it.

Bitcoin Core creates 100 addresses that it doesn't tell you about when you run it for the first time.  It then uses a new one of these hidden addresses for the change from your transactions every time you send a transaction.

I have a few Bitcoin Core wallets, so I have a few hundred addresses.

Then, it was recommended by Satoshi Nakamoto that you use a new receiving address for EVERY transaction.  I've done over a hundred transactions, so I have over a hundred receiving addresses.

I've also installed a few other wallets either to try them out or for specific purposes (such as MultiBit, blockchain.info, Mycellium, etc).

I've never counted, but if I had to guess I'd assume that I therefore have somewhere around 1,000 addresses.