hold on just to get this straight, do both the twins like haruhi?? o just one??

No Hikaru is in luv with her in manga kaoru just acts like he does so hikaru can realize it. kaoru values his "brothrly'' relationship mor and hikaru just thinks hes her ''toy''. kinda like how tamaki likes her exept he thinks of it as a daoughtr/fatr relationship. did tht help? and no i didnt get tht from wikipeia i rly do read the manga

I think both twins like her

Well (in the anime atleast), I think Hikaru likes her más than Kaoru but Kaoru pushes Hikaru into hanging out with her more.
So they both like but Hikaru like her más and Kaora tries to get them together because he is trying to be nice to his brother.