DS9: Sacrifice of Angels (Space Battle) and another one
Yes, this was an impressive space battle on a TV budget. I remember watching this episode and being totally in awe with grand scale of the battle. The fleet to fleet battle had a very Star Wars ROTJ feel to it. They used two FX companies to finish this episode.
-The smaller fighters attacking only the Cardassian ships.
-I love that the Klingons show up at the last moment and make a huge dent in the battle. That is a great moment.
Battle of Chintoka
The power source method thingy is certainly similar to Star Wars Episode I.