Supreme Commander

I found an extremely easy way to get this, To The Grave, Cherry Picking, and Hold Your Own at the same time. I believe it's much more efficient than Capta1n0bvious3 method, but he did have a good guide!! It gave me some good ideas.
You can actually rush the supreme enemy with your ACU in Assassination matches, and it's lots of fun! My fastest match was around 1 min. 15 sec. real time on a 5x5 map.
You MUST pick Aeon(best ACU for Commander battles--longest range and best attack), and the enemy CANNOT be Aeon--recommend enemy be Cybran because of lower ACU hitpoints and short range.

Select the skirmish match you need(34 maps total), with Fog set to None and Prebase set to OFF. Set enemy to closest location to yours at the start. Target enemy ACU with your commander and head straight there! On some larger maps, I had to build two Tier 1 turrets just out of range of the enemy ACU, and they would help me take out the base and ACU. Beware, enemy ACU's going critical deal from 500-5000 damage to your ACU. You will survive if you have more than 50% health, but watch out if you are lower!
You can survive most Commander 1v1's without the extra turrets because the AI gets messed up and doesn't target you most of the time--however, sometimes they have time to build some ground units that attack your ACU and things get really messy.... so your turrets come in very handy.
And, that's it! Repeat for each match. It's really funny watching the bad AI run around while it's getting shot at.

And, about the freezing!

If your game was freezing, I recommend making a backup of your game save, then deleting your Supreme Commander profile(ex. "Prefs 12/13/2014 - 5:31:48 pm" Saved game) from the storage directory on your xbox 360. This should help with the freezing, until your new SC profile decides to start freezing.. you should be able to run through all the Assassination maps before it starts freezing again like mine liked to do. It's a good idea to make a save at the end of each map and note down the exact time for the map. As long as you get to the main menu after the game without it freezing, you can be sure it saved.

To defeat the supreme AI i found some guides on the internet but they didint work for me this is my method

pick whichever map and put these settings
win condition Assassination
No Rush set it at 20 minutes
pre base ON
fog of war: explored
i used the UEF but i don't think the faction matters at all,
and set up the enemy to spawn as close as possible to your spawn point

so this is my method:

on your first land factory you set it up to do 15 engineers
2 engineers to just build power stations i placed 2 straight lines as long as i could go.
you should spend your first 10 min just upgrading mass extractors and creating power stations. at some point create 3 air factories
then around minute 10 upgrade all your air factories at the same time and have some engineers assist it should take 3 minutes max then put all factories to pump out level 2 gunships
by the time the timer is up you should have between 30 and 50 gunships at your disposal. send them to the enemy commander and you got a win, should take 22 minutes on normal speed after a while i could do this on fastest speed and it took only around 8 -10 minutes per map

**** before you send the gunships save your game, it tends to crash sometimes and it sucks wasting 20 min for nothing, if the game crashes reload your save and go for the kill again.
the map will not count unless your able to reload to the main menu. sometimes it dosent crash, sometimes it will crash 5 or 6 times in a row...i had to redo like half of the maps due to this issue since it seems when i was done i was missing one map. pretty annoying

I guess someone didn't like me sending you to another guide to find the solution so here it is here too:
I must first thank Gdinut for all his guides because without them this would have been much harder. I also PMed him once when I had an issue and he helped again so all thanks to him.
I believe I have found and easier way to get Controlling Presence, Hold your Own, Cherry Picking, and To the Grave at the same time.
I must emphasize that I didn't get it this way, but I got Controlling Presence and Cherry Picking at the same time so it should be possible.
They are stackable so if you get To the Grave you get the rest also.
Anyway set
winning conditions - supreme,
no rush - off
pre base -on
fog of war - explored or whatever it's called so you see everything. I can't remember what it's called.
winning conditions - 50%.
And set your opponent to the farthest away possible so they don't harass you.
Then Just start building Engineers, I usually build 30, that's way too many for any map.
Set your Commander to build about 10 Power generators.
Then send your engineers to capture the command points. I go from closest to farthest away.
You only need 1 engineer to capture any point.
If you are doing a big map, like 10X10 or bigger, have your first engineer build an air base and build a couple air transports. Then send an engineer in the transports to capture the farthest ones.
While this is happening, send your engineers to get all the ones close to you, you should have plenty of time.
When you're finished with that,then set your transports to assist the factory. Then set your LAND factory waypoint to close to the command points you want to capture. Hold down RB and when you see the hand grab it by pressing A, zoom out. The transports will load up 6 at a time and then bring them there. It's way faster than having the engineers slowly make it across the map. I cut my time down from 22-25 minutes to 5-10 minutes depending on the map.
Finally I found a way to minimize the freezing. Instead of it freezing about 70% or the time when saving, it only freezes about 10-20%.
Still ridiculous, but way more manageable.
First always save right before the game ends so if it does freeze, you don't have to do it all again. And you need to make sure it goes all the way to the next screen after where it shows the score at the end of the game.
If it doesn't, SOMETIMES it doesn't count. I had to redo several different achievements again because of this so it's good to make sure you have a save right before the end of every game just in case.
Right before saving, zoom all the way in, save, and then don't touch the controller until it finishes saving. I put mine down. It will save, showing the little circle, it looks like it finishes, but it doesn't, and shows the saving circle again. Then let the game continue for a few seconds after.
You have to do this when saving and at the end of every game and sometimes it will still freeze. It's really frustrating.
Is this totally ridiculous? Of course, but it seemed to help me a lot from freezing.
It also seems to help the longer you play in 1 session.
For example, it usually freezes the first time. Almost every time. Then after the second or third time it wouldn't freeze for the rest of the day if I kept playing.
Anyway sorry this is so long, good luck you few who play this game.

Edit: I forgot 1 thing. On the control point maps, they don't do all the maps. You need to do I believe it is 6 maps as a skirmish. Still this makes the vast majority way easier.