Many parts!
Here's a few:
Episode 16: Ichigo owns Renji
Episode 31: Ichigo owns Renji again!
Episode 39: Zaraki vs Ichigo
Episode 51-52: Zaraki easily defeats Tousen
Episode 59: Ichigo gives Byakuya a spanking.
Episode 60: AIZEN!
Episode 125: Defeats his inner hollow:
Episode 139: Gives Grimmjow a hiding then Grimmjow give him a hiding.
Episode 269: ULQUIORRA!!!!
Episode 270: ULQUIORRA!!!!
Episode 271: ULQUIORRA!!!!
Episode 308: I don't need to tell you!
Episode 309: I don't need to tell you!
Episode 310: I don't need to tell you!
Episode 339: Captains battling the Regai versons of themselves(filler but it was still awesome)
Episode 341: YUSHIMA VS ICHIGO (filler battle but it was still epic)
Episode 364: Tsukishima vs Byakuya
Episode 366: Battle Finale, needn't say anything more!