The general idea of changing things that are bad instead of sticking to traditions
Gay marriage and other rights
More efficient and affordable healthcare
Abortion (though ideally I'd find it fair if “paper abortion” was also a thing)
FOSS (though most people don't have a strong opinion on that)
Public transportation
Some things I like from the right:
General cautiousness about the negative effects of new policies (for example, schools catering to problematic students at the expense of the other students)
Trying to minimize unnecessary government intervention
Support of free speech (used to be a leftist thing, seems to depend on who is being censored more)
Cautiousness about illegal immigration
Banning of harmful addictive drugs
And what I don't like about either:
Takes on gender/race equality (left tries to achieve it but has a different idea of what equality looks like, right seems content with inequality)
Voter fraud prevention (right wants the requirement of a driving license or something, left wants no verification at all; I like the normal system of requiring an identity card that every citizen gets for free from the government)
Based on these, I'd consider myself centrist or maybe a bit left-leaning, but the far left would consider me a Nazi and the far right would consider me a communist or something.
Also note that I'm not from the USA and I see USA politics through the lens of what I know to work and not work in my country.