The current largest party, Pasok, is currently in third place behind the left wing coalition party, Syriza. New Democracy is clinging tenuously to the lead, probably more by virtue of being the only established right wing party in Greece than because they're doing something right. Independent Greeks and the Communist Party (KKE) are in fourth and fifth with the hardline Golden Dawn in sixth and newcomers, Democratic Left (Dimar), in seventh.
As it stands, with Laos and Ecologist Greens just shy of the 3% required to get a seat in the Greek Parliament (Laos is being punished for agreeing to join the last coalition before changing its mind), it would take a coalition of all of the opposition parties to keep Pasok and New Democracy from forming a coalition. Such a coalition would probably spell the end for Greece's involvement in the €uro and maybe even in the EU - something that the Greeks should be hoping for as the only way for them to get themselves out of their current mess.
Whoever ends up forming a government in Greece next week, one thing is for certain: the Greek parliament is going to be full of extremists. They'll have representation from the Stalinist KKE (Communist Party), the Greek equivalent of the BNP (Golden Dawn) and other minority far left parties. It doesn't bode well for a stable Greece but they've been in a state of virtual anarchy for so long now, probably nobody would notice!
For an excellent near realtime map of how things stand in Greece as the results come in, check out this from Infographics.