1, POW or POS?
2, Limited total amount like BTC or unlimited amount like XMR?
3, ASIC-resistant or ASIC-friendly?
4, With ICO or without ICO?
5, With or without pre-mining?
6, Dose development teams rewarded or not?
7, Or do you only care about price and whether it can bring you profit?
For me, anything that will not compare to Bitcoin or not will compete with Bitcoin. That's why altcoins are now called "altcoins" because they are alternatives to Bitcoin.
So for me, originality and uniqueness are important here.
Without ICO, it is good of course and without pre-mining, no team is rewarded. And best is it is open-source, driven by the community, it's a very fair to everyone.