I don't have experience with ASIC mining myself as I don't have a rig for it, but I could help you out with it a bit. Mining BTC isn't as profitable anymore as mining altcoins is.
If you're using an ASIC machine, SC (SIA) is a good option and will give you more profit than LTC, and especially BTC. With GPU mining, I'd just stick to Ethereum.
hey I been mining for 2 years now, ASICS are great- especially if your hydro is included. I got an s3 that's been running for about a year I got it for like 120 bucks, and over this year its made me over 300, so definately a good buy even older tech. the newer one's price is inflated, but you get what you pay for, it seems like slushpool favors users with higher hashrates, cause I get paid more per unit running 3 then just one, although that might be due to fluctuations in indevidual performance.
Keep in mind that ASIC miners only can mine SHA-256 encrypted coins, such as Bitcoin, and Litecoin. One that I would recommend is Peercoin, it seems to be going hard, it's profitable and it's SHA-256.
The only ASIC's that are actually worth it right now are the new cryptonight asics. They are profitable as fuck right now, but most coins will fork and it will stop working in a month or two.