The Clone Wars - S5E3 - "Front Runners"

5:16 - Obi-Wan:  "But we need to be mindful of public perception."  He uses the same expression in Attack of the Clones ("Be mindful of your thoughts, Anakin; they betray you" [12:29]) and in the previous episode.

14:06 - Steela:  "We're running out of time."  Qui-Gon also says this in The Phantom Menace:  "Either way, we're running out of time" [40:07].

14:45 - Steela:  "I'll draw their fire."  Red Leader says something similar near the end of A New Hope, as the assault on the Death Star begins:  "I'm gonna cut across the axis and try and draw their fire" [1:46:08].

16:29 - Steela (to Saw before he fires the tank's cannon into the power generator):  "You're all clear."  Han Solo uses this same expression near the end of A New Hope, before Luke fires his torpedo into the Death Star:  "You're all clear, kid.  Now let's blow this thing and go home." [1:56:54]

20:27 - As Dooku introduces him ("This is Kalani"), Kalani steps into the hologram in the same way that Darth Maul steps into the hologram when Darth Sidious introduces him ("This is my apprentice, Darth Maul") in The Phantom Menace [27:38].  The relative positions of the two characters are also similar:

21:43 - Steela (explaining to Ahsoka why she can't just let Saw leave):  "He's my brother."  Leia also says this in Return of the Jedi [2:04:03].

The Clone Wars - S5E2 - "A War on Two Fronts"

12:13 - Obi-Wan (to Steela):  "Be mindful of your frustration.  It will only hold you back."  In Attack of the Clones, he uses the same expression:  "Be mindful of your thoughts, Anakin; they betray you" [12:29].

14:55 - Anakin (after Steela shoots a target):  "Impressive.  Most impressive."  Vader gives the same compliment to Luke in The Empire Strikes Back [1:44:30].

16:21 - Obi-Wan (to Anakin, about the rebels):  "We can only protect them; we cannot fight this war for them."  This echoes what Qui-Gon says to Queen Amidala in The Phantom Menace:  "And I can only protect you; I can't fight a war for you" [1:37:45].

16:29 - Obi-Wan (about the droids):  "There are too many."  Captain Panaka says something similar in The Phantom Menace (referring to battle droids):  "There are too many of them" [23:25], as does a Jedi youngling in Revenge of the Sith (referring to the clones executing Order 66 at the Jedi temple):  "Master Skywalker, there are too many of them" [1:23:40], and a rebel pilot says basically the same thing in Return of the Jedi (referring to TIE fighters):  "There's too many of them" [1:35:13].

17:10 - Obi-Wan (to Steela, referring to a droid tank):  "We'll handle this."  Qui-Gon (referring to himself and Obi-Wan) also says this when Darth Maul appears in The Phantom Menace [1:50:29], although Obi-Wan also says something similar in Attack of the Clones (about fighting Count Dooku):  "Anakin and I can handle this" [2:03:07].

19:41 - Battle droid (to the rebel convoy):  "Halt!"  In The Phantom Menace, a battle droid also says this to Qui-Gon as he leads a group of Naboo to a ship [24:25].

21:11 - Lux Bontari:  "Good luck."  It's ambiguous whether he directs this to Steela or Ahsoka, but in The Empire Strikes Back, an unidentified Rebel pilot wishes Luke good luck [36:02] and Luke wishes Lando good luck [2:00:09], and in Return of the Jedi, Han and Lando wish each other good luck [Han to Lando at 50:33 and Lando to Han at 52:21].

The Clone Wars - S5E1 - "Revival"

2:37 - Maul (to Savage):  "Always two there are, my brother, a master and an apprentice."  Speaking to Mace Windu, Yoda says almost the same thing in The Phantom Menace:  "Always two there are, no more, no less, a master and an apprentice" [2:07:59].

3:12 - Maul (to Savage):  "And I shall complete your training, not as your brother but as your master."  Vader uses the same expression in The Empire Strikes Back when he tells Luke, "Join me, and I will complete your training" [1:50:39], and the Emperor uses it in Return of the Jedi (also speaking to Luke):  "I am looking forward to completing your training" [1:31:04].

7:20 - Maul:  "Hondo's base will soon be ours, and he will not survive this."  Near the beginning of The Phantom Menace, Rune Haako says something similar as the Jedi cut down battle droids:  "We will not survive this" [6:12].  There's also some resemblance to what Palpatine says to Luke in Return of the Jedi:  "And your friends on the Endor moon will not survive" [1:44:25].

14:27 - Hondo:  "Retreat!  Retreat!"  Jar Jar also yells, "Retreat!  Retreat!" in The Phantom Menace [1:56:53].

18:25 - The cockpit of Maul and Savage's ship features yet more uses of the hexagon design seen in the homestead garage in Attack of the Clones and A New Hope:

The Clone Wars - S4E22 - "Revenge"

10:25 - Mace Windu:  "This is clearly a trap."  The context here is different, but Admiral Ackbar says, "It's a trap!" in Return of the Jedi [1:35:03], and Leia says it twice in The Empire Strikes Back [1:39:50].

12:56 - Maul (to Obi-Wan):  "I have been waiting for you."  Vader greets him the same way in A New Hope:  "I've been waiting for you, Obi-Wan" [1:30:09].

17:42 - Ventress (to Obi-Wan):  "It looks like I'm here to rescue you."  Luke says the same thing to Leia in A New Hope:  "I'm here to rescue you" [1:16:09].