ETH would need to change to PoS first, in order for staking pools to become a reality. While there's already a staking pool in the works (named Rocket Pool), it's not functional yet as Ethereum is still a PoW cryptocurrency. However, knowing this allows us to gain an advantage before PoS becomes a reality within the Ethereum blockchain. One could easily invest into ETH while it's still a PoW cryptocurrency, to stake it later on a staking pool like Rocket Pool.
As for other cryptocurrencies, the only safest bet would be StakeNet's Trustless Proof of Stake algorithm. This provides the same benefits as staking pools, but without the added risk of exposing your private keys to a third party. Given how many phony staking pools there had been lately, people are looking for alternative solutions which are decentralized.
So far, we've got XSN's TPoS algorithm for trustless staking and ETH's decentralized staking pool. Additionally, we have the option of staking some cryptocurrencies in a VPS by using multi-signature addresses for additional security (see Multi-signature staking on Google).
Nonetheless, I believe that the only staking pools that are good right now are those which are decentralized. Other than that, it would be a waste of time and money. Just my opinion