That depends on your values, where you live, and what matters to you.
If you're a multi-billionaire and don't care about other people much, then you should logically vote Tory.
If you're one of the 99.9999999% who is not rich, even if you don't like other people much, then you should probably vote Labour, Green or maybe Lib Dem.
If you don't live in the south, south-west, Brighton or Bristol, you should probably vote Labour as they're more likely to be in with a chance of winning. In Brighton and Bristol, a vote for Green may win them a seat or two. In the south and south-west, the Lib Dems are more likely to beat the Tories.
If you live in Scotland, you could choose from SNP (esp if you want independence or more control of Brexit) or Lab/Lib Dem depending on what part you live in. Again, vote Tory if you're incredibly rich and hate everyone else.
In Wales, you could vote for Plaid Cymru, who are a bit like Labour only Welsh nationalist. But if you live in the valleys, your vote is more likely to count voting Labour. In Cardiff you could vote Green or Lib Dem in a few seats where they may win.
If you live in Northern Ireland, I apologise. Vote Alliance for non-sectarian, SDLP for Labour-like slightly Republican, Sinn Fein for unity with the rest of Ireland, DUP if you dislike Catholics and Ireland, UUP for a bit less of hating Catholics but a bit more Tory.
On top of that, here are a couple quizzes that might help you decide who your party may be:
http://www.whoshouldyouvotefor.com/
https://voteforpolicies.org.uk/
The second link is much more accurate, but based on 2015 election manifestos. Also a manifesto is not really a promise of policies that will be delivered, it's more of an indication of the values the party in question believes in.