"Battle on the Asteroid" from "The Hand of God"
The first battle is from the episode, "The Hand of God," where the fleet has decided to take the fight to the Cylons so they can acquire control of a tylium-rich asteroid that can fuel their jumping for at least two years. Even though Starbuck came up with the plan to outsmart the Cylons, she has to stay behind and monitor the attack aboard Galactica because she has yet to recover from the injury she sustained after crashlanding on a moon back in "Act of Contrition." Now, it is up to Lee, so her concerns are warranted, although he does end up proving himself in the end - because he tries to think, "What Would Starbuck Do?" Basically, Starbuck lures the Raiders guarding the asteroid into attacking Galactica by pretending to use decoy ships (that are instead loaded with Vipers), and then Lee and Company destroy the tylium refinery by using Baltar's wild guess (they didn't know it was just a random "point at a spot on the picture," but because this is Baltar, he now thinks he truly was guided by the "hand of God," hence the title of the episode) and firing at a specific part of the Cylon base. Lee's choice to go through the refinery on a hunch was actually one of my favorite parts, despite the fact that Lee is awful, as is the moment where Roslin is like, "Uh, guys, you didn't let me in on a pretty big aspect of this plan of yours." Like a lot of the first season, this successful mission is one of those that have no real bittersweet moments, since pretty much everyone (sigh, poor, poor Chuckles) returns unscathed and they're all pretty happy with themselves. It is definitely in contrast to my second choice of favorite battles.
"Storming New Caprica*" in "Exodus, Part 2"
I've already gone into detail about this episode on Day 16, but I will say again: "Exodus" is the single best episode(s) of Battlestar Galactica. It's usually the one that I show people that have never seen it or lost interest after the first season. This battle has Galactica jumping in and out of the planet's atmosphere, Vipers flying everywhere, Tigh, Tyrol, and the rest of the resistance evacuating the civilians, Three searching for Hera, the Cylons trying to figure out what to do (nuke the planet? okie dokie), Baltar almost getting shot by Gaeta (sigh, Gaeta). It's intense and beautiful and sad and elating, and everyone's performance is amazing. And the music? Top fucking notch. Of course.
And you know what? I'm going to go watch this episode again. Because I can. Thanks, Netflix!
* I am not lying when I say that I listen to this almost every day. I love every single part of this.