I am only currently interested in two cryptocurrencies. I only own Monero, and I only use Bitcoin to buy Monero. Some people will think that is crazy (probably most people), but I think it is A. my best chance to make money in the world of cryptocurrency, and B. the best looking crypto that exists, and probably will be that way for at least another 3-5 years.
1. Monero, it is in my opinion the only crypto of its kind. I understand it is hard to use for a lot of people right now/has a higher barrier to entry for people that aren't as techie, but I think this makes it that much more undervalued. I believe it has the best anon tech around, no flashy gimmicks. This is -incredibly- valuable. It doesn't suffer from the fungibility problems that I believe will plague non-anon cryptos in the next few years. Fungible money is of the utmost importance. Monero is also on a completely different codebase from Bitcoin, I think this makes it an incredibly valuable alternative and also a great hedge in the event of Bitcoin suffering from any misfortune, such as a hardfork (1mb blocksize limits).
Monero has a pretty awesome name, once it grows on you. It means coin in Esperanto, an international language.
Monero is CPU and GPU minable right now, which is the best. GPUs only slightly outperform CPUs, and it will forever stay that way, which is amazing, and IMO the best. period. When ASICs come out for Monero, they will only perform about 5-8x better according to some researcher of the algorithm, which is awesome. period. I think ASIC developers should be rewarded for their efforts, but not just given everything like in fucking bitcoin.
Monero is perfectly fungible thanks to its anon tech, I believe that there is not a single other cryptocurrency that can claim this, so that is a pretty big win there.
I don't like PoS, I think it is basically a scam, but I don't really want to get into describing why because it is easy to understand.
I can also use my Monero to pay for any bitcoin service anonymously thanks to xmr.to a webservice that does what I just described.
So check Monero out if you haven't. Feel free to PM me if you have questions, I'll try to answer them or at least point you towards someone who can.
2. Bitcoin. I list Bitcoin under Monero for many reasons. I love Bitcoin, it is the OG of peer 2 peer decentralized electronic money. Bitcoin has its fair share of problems though. My biggest beef with Bitcoin is the current state of mining. How is a decentralized currency supposed to remain decentralized if the miners/processors of transactions are so few? Only about 10 ASIC manufacturers are responsible for ~90% of the mining for Bitcoin. This is a HUGE problem! Bitcoin, in my opinion might be destroyed by this. It entirely goes against Satoshi's vision of 1-CPU 1-Vote. Monero doesn't have this problem, and will likely never have this problem. Monero is and will forever be CPU, GPU, FPGA, and ASIC friendly for mining, and does it with extreme fairness. This is much closer to Satoshi's vision than even Satoshi's child, bitcoin.
Next, we have the issue of 1mb block size limits. I don't claim to be a genius who knows all the details on this, or how to fix it, what I do know is that the community is split on what the answer going forward is, and that it will need a hardfork most likely to fix. This is bad news. Monero does not have this issue, it has no limit on blocksize that scales with the network already hardcoded into it.
Fungibility, this is something that everyone should familiarize themselves with if they haven't already. We already know that you can divide a bitcoin pretty much infinitely (or down to 1 satoshi right now) but, the problem of Bitcoin's fungibility comes from the fact that you can trace every transaction on the blockchain. lets say regulation enters the bitcoin space, and criminals or even law abiding citizens caught with *marked* coins (coins that were stolen, used for illicit purposes like drugs/money laundering/whatever) can't spend their coins anywhere. all of a sudden this becomes an issue. This has already started to surface, if anyone remembers BTC-e trying to block the sale of bitcoins used in the Evolution exit-scam, and there have been a few other cases. So, it is entirely possible that some ordinary Joe, decides to buy some bitcoins, he accidently obtains tainted coins, and now he can't do anything with them. Monero doesn't have this problem because it is anonymous, therefore you can't tell if a coin is tainted or not.
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Since the OP wanted 5 coins, I will list some more, but I do not hold any of these coins really, only mine some because I was suckered into buying some ASICs, hooray me /s
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3. Namecoin. This coin offers some incredible domain hosting stuff or whatever it is called lol. I am honestly not too knowledgeable on the details, but I was impressed with what I saw. I like it because it is unique and actually adds something usable, though it suffers from a lack of development.
4. Litecoin. This coin is actually what got me interested in cryptocurrencies though I have known of bitcoin since early 2010. Too bad for me I didn't get involved until 2013, when I decided to mine some Litecoins on my GPU, but oh well, learn and live. I still mine some Litecoins on my KnC ASICs, but I sell them for Monero as I mine them. I think Litecoin sucks now and has practically no use anymore. I consider it a failed experiment due to ASICs and the fact that you cannot GPU or CPU mine it. It is kind of interesting because it is very slightly different than Bitcoin, but it truly has no use. I don't think it will die for another couple years though, and maybe if the devs for it come up with some radical new ideas it could live forever, but I doubt it. It does have a decent name though, but that doesn't give it any real use.
5. Primecoin. I like it because it looks for prime numbers (at least I think it does?) so that is kind of neat. I mined some on a few servers and made some money back in 2013, so that was fun. It is junk now though, though if it breaks more prime number calculating records I will think that is cool and possibly useful to some mathematicians or scientists, but probably not.