The first two are actually running on a joint list, and LMP is a new Green formation -- and indeed my likely vote.

MSzP are the Socialists, backers of the current 'expert' minority government. While it's not as bad as for you with Romanian parties, I guess even this much similarity is due to the flowery nature of the party's Europolitics/rhetorics -- I don't approve of many of the government's policies.

Fidesz is the main opposition party, a right-populist outfit. In addition to the above reason, similarities may come from their social populism. (Which is balanced by their recently resurgent insane tax cut populism.)

MDF is a small conservative party with a recent neoliberal makeover.

SzDSz is the liberal party. Methinks on non-economic values, I am still more similar to them than all the other main parties, so weighting matters...

Jobbik are the neo-fascists. That similarities aren't zero must come from their social protectionism.

_{*Lunatic*, n.
One whose delusions are out of fashion.}