Vehicles painted red? Yes.

Guns painted red? Not so much. Now guns painted yellow? Oh yes!

Gunz painted blue would be more useful; who needs money when you got Luck.

But if the guns are painted red....THEY SHOOT FASTA!

Youz need red bullets fer dat ya Grot!

Yah paint em yellow to make da bullets explode like Dem Space Marine Shootaz.

Definitley some sort of WAAAAAAAAAAAAAAGH!!! ability, its pretty iconic for orks.

My top 3 are these
Ammo runt:Refill ammo ability (only useable once until you die)
Green tide: The more orks you are around, the faster you run and the higher you're health is/better dmg
Dakka Dakka Dakka:Faster fire rate/damage at the cost of accuracy
and maybe for a commander ability we can have a stheel rehn Rok bombardment.

As as standard on the table top the Waagh ability of Orks is that in large groups they get bonuses to moral and close combat, if the group is big enough they are immune to breaking and never have to take fear or terror checks.

The ability to loot Carnifexes as a personal mount.

If I'd want to get it in order:

1. Power Klaw... seriously, ork without one is less orky
2. Bosspole! A warboss is not a propa boss without a shiny bosspole with trophies hangin' all over ^^
3. The right n' proper dakka: Rokkit Lancha, snazz gun, big shoota, loota, beamy deffgun, Zzapgun, shokk attack gun!!(with snotling ammo ofc :3), stikkbombz, ect...
3. Looted tank!! especially with the ability to make a looted tank of any captured enemy vehicle (mostly SM/CSM tho, I doubt we can use shiny eldar stuff... the delicate controls just break on touch :/)
4. Squigs Like... bomb squig :3 Similar what was in Space Marine (god they freaked me out the first time xD)
5. Squiggoth :3 As mentioned before ^^ the smaller one (Leman Russ size)
6. Meks able to make cybork implants :3 And bioniks Orks are not proper without a lot of mechanical bitz ^^
7. Mega Armor 8) need I say more ?
8. Kombi weponz, who the heck would not WANT one ? Ok, maybe a nob with a nice big hammer... but seriously :3 too nice to pass up ^^
9. Killa kan/Deffdread Got to love that silly walker
10. Gretchin ammo carriers and mobs They would add a nice crazy mood for the already crazy fight xD

Lol I could go on for a while x)

Well TT is like a strategy game. I dont count morale in EC because you will be controlling an individual warrior. Not a whole army or a squad of warriors. I think in a game like this morale should depend on you, and on you only, that way an ability dosen't decide if you're "scared" or more "brave". Morale should still play some part in the game, just problably not the way you're thinking