I actually disagree that Doge has no use case "because it's a meme coin". Doge has an independent blockchain, so it is a platform where a lot of things can be built upon, like
Doginals last year, which allows to create NFTs and memecoins on top of Doge. This is also a big difference to most other meme coins, like Shiba or Dogwifhat which are simple tokens.
Doge is merge mined by LTC miners so it should have currently the highest security of all proof-of-work altcoins. The number of transactions is highly volatile but in the first days of July there were
as many Dogecoin transactions as there were Bitcoin transactions. Normally it swings wildly between 15-30% and "more than Bitcoin". So there is actually some usage.
By the way I'm not invested in Doge, because it was extremely volatile in the past, and as others have mentioned, a lot of its value in the past 4 years was related to speculation about Elon Musk and Twitter. I dunno if this "bubble" has already burst completely, i.e. if it's already priced in that a mass adoption due to Twitter simply hasn't happened. But in general Doge was less volatile in the recent past, so it
may be a good opportunity to enter at current prices. I would not bet on it however.
So suggest me some alt coins.
If you're in for the long term, then I suggest
this list or
this list (slightly looser criteria), these are coins that are similarly decentralized than Bitcoin. The second list contains Doge, LTC and Kaspa, for the first list's creator these three aren't decentralized enough but instead Monero (XMR) was the biggest "decentralized altcoin". Nobody can know however if they will go up. But they solve real problems, in contrast to most premined altcoins.
About XRP: It is holding relatively well but it's actually one of the most centralized blockchains (not including tokens).