I personally favor coins with good decentralization feature. Bitcoin is the king because massive power of miners supporting network. They effectively transform electrical power into valuable coins securing network at the same time. Steem and BitShares are also well decentralized with use of DPOS algorithm where witnesses compete to get best positions for their block producing nodes.
ETH, ADA, DOGE, Monero, EOS and many other coins are well decentralized too. But stay away from Ripple, ITOA, NEM and maybe some others where closed teams are behind them and controlling their networks in great extend.

I also not prefer centralized exchanges (Bitfinex, CoinBase, Bitstamp, Kraken, .....) because a lot of personal information is gathered there which can compromise you and heard your anonymity. I strictly trade on BitShares and waiting also on OmiseGO platform to fire up. His coin is also very bullish at the moment (+5% at the time of writing). BitShares don't hold any of your personal data and there is no company behind BitShares. It's blockchain handles everything and exchange there is fast , chip to operate, reliable and your funds are under your full control, because you hold private key of your account there.

Read more about in one of my old articles: Why IRS can bust you on centralized exchanges and not on Bitshares!.