Aris vs Panathinaikos this weekend. Should be an interesting one - Aris is in 4th place, which would be big for their EL participation (or at least, chances of qualification). Atromitos, who is in 5th, plays them next weekend (while having an easier game on Monday).
Otherwise, Xanthi-AEK and Panaitolikos-Olympiakos are going down on Sunday. Not much danger of the standings changing, though I guess if AEK loses their next two games they could end up worried. Very unlikely.