For my Iron Hands this is a simple and much underused choice, Close Combat Scouts. I tend to run a full unit of ten including a Sergeant with a Power Fist, it is a bargain for a whole 165pts. They are so versatile and are a ideal speed bump, especially as mine tend to be Stubborn (via Lysander or Pedro), couple that with Pedro's Inspiring Presence and they have 36 WS3 S4 attacks and 4 WS4 S8 Power Fist attacks on the charge, its enough to put a serious dent in almost any unit.
Considering my Dwarfs this again is a simple choice a unit of 18 Ironbreakers. This provides a good solid heart to my forces, couple that with a runic banner and either a Lord or BSB and they are very hard to shift.