"Gettysburg" to start with, which of course depicts its namesake battle - but glosses over many of the sub-battles and focuses a lot of a few of them - Bufford's defense on the first day, Longstreet's advance and the defense of Little Round Top on the 2nd, and Picket's Charge on the 3rd.
Gettysburg's prequel, "God's and Generals", which showed 1st Manassas, Fredericksburg, and Chancellorsville - I believe the extended version on DVD / Blu Ray also showed Sharpsburg but I've never seen it.
"Cold Harbor" is more of a civil war period piece and as I recall does not actually include its namesake battle, but does contain the famous portion of the seige of Pettersburg known as the battle of the Crater.