Okay, so me and a friend are going to have an evening where we ignore restrictions on upgrade cards and have inter-faction lists. I need help in coming up with the most broken list possible.

All the Sabine in one list.

This sounds like fun, and there are a few ways to go. If you're ignoring all restrictions on upgrade cards - including the number of bodifications you can have on a ship, then a Ghost with as many stealth devices as you can get would be pretty broken -it's at least 20 agility plus an evade token. However, I suspect you're just talking about the "limited", "unique", "x ship only" and "one faction only" restrictions.

3 Fenn Raus could be a tad ridiculous. Come to think of it, so could 3 Soontir Fels, or any other high PS ace.
Two Biggs Darklighters would break the game in your favour. Fly them at range 1 of each other and your opponent will almost never be able to attack.
5 Unkar Plutts would be hilarious.
Two Corran Horns would be nigh-impossible to kill.
Be totally unpredictable and run 3 GR-75 transports and ram your opponent to death.
Corran horn with VI and an Advanced Cloaking Device is hilarious in a lot of ways.
3 Party Buses with Zuckuss would be amazing. Maybe one with a tractor beam and Ketsu too.

Double Sabine Mirandas

(100)

Miranda Doni (50) - K-Wing
Twin Laser Turret (6), Extra Munitions (2), Sabine Wren (2), Seismic Charges (2), Cluster Mines (4), Advanced SLAM (2), Thermal Detonators (3)

Miranda Doni (50) - K-Wing
Twin Laser Turret (6), Extra Munitions (2), Sabine Wren (2), Seismic Charges (2), Cluster Mines (4), Advanced SLAM (2), Thermal Detonators (3)

Or 2 Mirandas and a captain Rex for 3 Sabine crew

Miranda Doni (41) - K-Wing
Extra Munitions (2), Sabine Wren (2), Seismic Charges (2), Cluster Mines (4), Advanced SLAM (2)

Captain Rex (18) - TIE Fighter
Sabine's Masterpiece (1), Captured TIE (1), Sabine Wren (2)

Miranda Doni (41) - K-Wing
Extra Munitions (2), Sabine Wren (2), Seismic Charges (2), Cluster Mines (4), Advanced SLAM (2)

or 4 Captured TIEs at 25 a piece for 4 sabines.

Ahsoka Tano (25) - TIE Fighter
Veteran Instincts (1), Sabine's Masterpiece (1), Captured TIE (1), Sabine Wren (2), Proximity Mines (3)

This was batted around a lot when somebody was planning for an "any title any ship" game. Any number of aces with IG-2000 is blindingly unfair.

Like, imagine Fenn Rau, Redline, Palob Godalhi and Omega Leader, all with IG-2000. Leaves you with 4 points worth of upgrades. Or replace Palob with Sabine for 9 points of upgrades.

Or, for slightly less obnoxious cheese, you could do Omega Leader with Tie Shuttle and Weapons Engineer.

Generally, whatever list you end up with? Add in a bunch of the 0 point titles. Just to screw with your opponent big time. Want to always throw an extra attack die? Enjoy Alliance Refit or Special Forces Tie. Want to fly speed demons? Put x7 or adaptive ailerons on everybody.

Heck, if you're going to go for IG-2000, just toss Fenn, Inquisitor, and Talombane Cobra in a list and call it a day. The list basically flies itself. Maybe some Push the Limit, a couple of Autothrusters. Stick at range 3, defend with two bonus dice, and still hit with 6 attack dice every turn.

4 biggs, error 404 as mentioned.