Biggest fail has to be AMP - put around $1000 into it when it ICO'd, and it hasnt really done very much. I'm still up overall, but not as much as with some other projects. If i'd have put that $1000 into XRP or SIA, at the same time, instead of very conservative amounts, then I'd be a fair bit richer... Cant complain though, no real losses to speak of yet. :)

However, I think my biggest 'win' has been creating a platform for discovering and researching ERC20 tokens, and exploring the Ethereum network. Giving back to the community by building a (hopefully!) useful tool is a nice feeling.

You can check it here if you are interested - https://steemit.com/cryptocurrency/@sroka87/trivial-a-powerful-ethereum-network-explorer-what-can-it-do