This is my first dreadnought list so tell me what you think!
I am only using what I have, never been a fan of proxying to much.

Relic Blade, Stormbolter Artificer Armour
Command Squad, x4 Flamers
Rhino with Hunter-Killer Missle - 328 points

Stormbolter, Terminator Armour, Epistolary - 180 points

Tactical Squad
Plasma Gun, Power Fist, Plasma Pistol, Plasma Cannon, Melta Bombs - 230

Scout Squad
Snipers x 4, Heavy Bolter, Camo Cloaks, Melta Bombs - 105

AoBR Dreadnought - 105

AoBR Dreadnought
Drop Pod with Beacon - 150

Ironclad Dreadnought
Heavy Flamer, Heavy Flamer, Hunter Killer-Missles x 2, Drop Pod with Beacon - 215

Heavy Support
Devastator Squad
Heavy Bolter x2, Missle Launcher x 2 - 230

Main tactic is to create a "base" with Librarian joined with Plasma tactical in ground level cover. Scouts directly above or close in 2-3 story cover. Devastators in cover aswell.
Captain and Command Squad advance in Rhino, using the walking Dreadnought as cover.
Drop Pods bring in whatever is needed first turn (Horde being Ironclad, Armour being the AoBR Dread).

List improvements will probably be removing the Captain and Command squad and putting in a Master of the Forge, a Drop Pod or two for the tactical and Walking Dreadnought. Then get another Dreadnought with twin-linked lascannon with missle launcher.