Apart from Bitcoin, Litecoin is perhaps the oldest coin I have in my wallet right now. I lost the vast majority of my LTC holdings when BTC-e/Wex.nz closed down, and then again lost some when Cryptopia ceased its operations. So my current holdings are rather small. Apart from Litecoin, I have some Ethereum and Stellar Lumens in my wallets, but these coins are not that old.
Litecoin is a good-old coin worth looking today. The development team has proposed Mimblewimble for LTC, in order to bring a whole new level of privacy to the Blockchain. If successfully adopted, MW could drive Litecoin all the way to the "headlines" like in the past. It's no secret that Litecoin is faster, cheaper, and much more flexible to manage with than Bitcoin itself. LTC alongside, ETH and BTC, are one of the best old coins you can "hodl" right now.
Another old coin worth mentioning is Dogecoin. I've been "hodling" Dogecoin since I got into crypto nearly 6 years ago. Faucets pay a good amount of DOGE, probably because of its inexpensive price across the market. I know that Dogecoin has an inflationary supply. But the fact that the community still supports it, makes it a good coin to "hodl" for the long term. A great use for DOGE is tipping and micropayments at a fraction of the cost of both Bitcoin and Litecoin. I've noticed that some old coins have been abandoned by people in the mainstream world in exchange for newly-hyped ones. It's not to my surprise, since people are on the look for the next big thing in crypto. Because of this, some old coins have very low trading volume and a low price on the market. What truly matters is not the price, but how useful a Blockchain network is for decentralized and censorship-resistant payments worldwide.
Nonetheless, it's best to "hodl" old coins for the long-term because they've been tried-and-tested over time. Developers have worked hard over the years in order to make these cryptocurrencies resilient against most attacks in cyberspace. That's not the case with newer coins whose technology is untested. If people want to have confidence that their "crypto money" will be safe for many generations, it's best for them to choose an old coin over a new one. Despite this, anyone can decide to support one coin from another. Just my thoughts