Glory Hogs turns Tankbustas from being average to being bad.
This. Tank busters suffer from having this rule. Badly. Totaly not worth the points that you spend on them at all.

Kommando's should have Snick as he makes them that much better and with 2 burners they become very good.

'Ard boys only really work against Marines and even then they arnt really worth the extra cost to get them.

Pain boys make orks great.

Loota's are fantastic if you can get decent rolls with them

Shoota boys are better then close combat boys.

Deffkopters are good if used correctly.

That said all of this advice is only applicable if you have decent rolls.