Judging from the way Elon Musk has been shilling Dogecoin in the last couple of weeks, I'd say Doge is mostly on his list of favorite cryptocurrencies. It isn't just these past weeks. If I remember correctly, in the past year, he has posted a thing or two about doge so it's nothing new. Also he doesn't necessarily need to buy and hold dove for it to be his fav coin. He might be shilling it and not owing even a single piece of doge. I saw a recent tweet about Elon Musk buying some doge for his son so he could be a hodler. I don't know how true it is but it's his account.