Marvel vs. Capcom 3: Fate of Two Worlds

An "Uncanny Combo" is a combo with more than 91 hits.

Start Offline/Arcade Mode, using

Ironman - Deadpool - Modok

with default attacks
Difficult: Very Easy
Time: Unlimited
Damage: Lowest

Build up your Hyper Combo up until you have three full bars.
Wait till you get an enemy with almost full health and press Left Trigger (LT) if you are using default controls.
All three guys will come out at once and perform their Hyper Combo and you get +91 hits

i got mine by putting the settings the same as skin coat said, but i found it a bit easyer to get it on the final fight. build up your hyper bars until you have three, and wait for the 2nd fighter to come out. i use ryu, akuma, and dante, waited until both fighters where lined up and chained two hyper combos together and had more than enough hits to get it. hope this helps

For this achievement you'll want to reach an Incredible Combo, or 91-hit combo. This can be achieved by using Iron Man, Modok, and Deadpool. Be sure to set damage on lowest and work to earn your Hyper Combo level 3, then be sure the enemy you use it on has near full health and use your Hyper Combo finisher. You should get a 91-95-hit combo for this 30G achievement.

Also here is a list of all the other combo titles for your convenience:

3 — Yes!
5 — Cool!
7 — Good!
13 — Dude!
17 — Sweet!
21 — Awesome!
26 — Wonderful!
31 — Viewtiful!
37 — Excellent!
43 — Stylish!
50 — Fantastic!
57 — Amazing!
65 — Incredible!
75 — Mighty!
82 — Marvelous!
91 — Uncanny!
101 — Crazy!
111 — Galactic!
201 — Unstoppable!

As said use the settings that skin coat used but use dante arthur and ryu now run close and do the team ultra (hold LT) should get u 91 exact and the achievement should unlock