Collecting a large variety of imperial guard is somehow very rewarding. The different guard regiments are distinctive in their look and their fluff is interesting. It’s just a shame that the official range of imperial guard are some of the smallest minis in size [Ed: though Slick Devlan is probably the smallest of the lot].

The official range of imperial guard is limited, but there are many 3rd party options.

Praetorian Guard (a Hidalgo-Beneito mini with a lasgun) and a Commissioned Officer with Bolt Pistol (Black Army Modells)
Valhallan Ice Warrior and a Kasrkin of the 8th Cadian Regiment (sculpted by Volomir)
Cadian Shock Troopers in Carapace Armour (Black Army Modells)
Mordian Iron Guard (Black Army Modells)
Sgt Dorian Black and Medic
Catachan Jungle Fighters (a Hidalgo-Beneito mini on the left), one with Rotor Cannon (Andrea Dark Nova mini on the right)

I still have a few more guard to paint up. Even some Vostroyans i want to convert from those plastic Tehnolog polar soldiers.