My speculation is that xmr will continue its steady longer term appreciation trend, with much less significant volatility than other leading crypto (BTC, ETH). In the long run, XMR will appreciate significantly more than BTC, as it's use cases are greater, and the current valuation is 50x lower.
Depending on your criteria, you might deem various issues as "leading crypto" but market cap per se is clearly meaningless. Bytecoin, dash, zcash and ripple are prime examples of that meaninglessness, for distinct reasons with similar implications, i.e. in each case the cap far exceeds the float - liquidity stinks, and every "greater fool" that comes along is just burying themselves under a deeper and deeper creaking overhang. I do not deem any of these four in particular to be in the class of "leading crypto". I still hope for a fair community launch of a zksnark crypto (or the incorporation of zksnarks into xmr.)
ETH is definitely leading crypto, but can't be classed as a monetary asset per se. It is also heading for a legal and social catastrophe at an ever accelerating pace. I much prefer the tortoise-style victory to which Monero is iterating, steering far clear of the snake oil and Ponzi complexes that besmirch the very concept of crypto. The political and governance risks of XMR seem clearly to be much less than those of either BTC or (most especially) ETH.
Bytecoin - I do not know. Sounds just another coin, Monero is a fork from it?
Dash - A good coin, very professional community and a good business plan.
Zcash - Probably will take over Monero in terms of marketcap
Ripple - used by the banks, banks have money, has bright future.
ETH - No direct rival to Monero. Different type of an asset and thanks to amtitious and apparently hardworking Vitalik who enjoys apparently hotel living it will have bright future as well. One of the big regrets I did not invest in the crowdsale. Even a smallish investment worth now million usd. Unless bitcoin will not get a major pump any time soon and stay new highs, chances are ETH will become the largest crypto.