Mechs are one of the areas where it's hard to feel creative. You have legs, arms, guns, and if it's driven by a human, a cockpit towards the center. Even while putting this together, it's hard to feel I'm not being creative enough; but hopefully this will help others.
20170821 by Yulin Li
The first of the 4 arm mechs. The variations in size, as well as the accessories give the impression of a very capable all purpose bot.
White and Gold by Maung Thuta
I wanted to start this list off with a simply really solid design. The white/gold/black combination is a classic at this point, but one I find very visually stunning.
Reconnaissance Robot by min seub Jung
This guy plays into my love of advanced, gritty tech. These arms and legs aren't something it stands on; they are things it searches with. Even the switch to sets of 3 is nice.
Hunchback by Tomi Väisänen
I love mechs that are burdened. Just absolutely weighed down with all sorts of things. The hunch, the legs; all of it works together to give you this very slow and deliberate force.
Desert Runners by Daryl Mandryk
For some reason I really love the cockpit positioning and the height of the gun arms. The general position of the cockpit isn't too abnormal; it's fairly centered. But the bit extra that it goes out, giving the pilot a better view below gives the design a lot of personality.
Bulgasari
Who needs arms when you have enough rockets to deal with any threat?
Furrion Exo-Bionics by Min Guen
I like the stability of the 4 legs. It reminds me of TRON
picnic by puz lee
Nocturnal Butterfly by Denys Tsiperko
Some Sketchtember Stuff by Thomas Chamberlain-Keen
TinyWar by Trevor Claxton
BOO-HOO a giant robot is storming the base :( by Alessandro Baldasseroni
Very humanoid in shape, but we have smoke stacks. Most of this list contains designs that are simply futuristic. This earns points for being an alternative universe/tech combination.
Battleborn ISIC by Skyup Academy
Cardio by Andrew Mar
I think the design is really cool; and beyond that the scene is just great. If the mech was by itself, I would assume it was built to do damage.
Mecha - Sagittarius by Lin Hongy
Weapons Mech by Hamish Frater
Neo Nippon 2044 : The Beach Patrol! by RUPAM RAAJ R.
submaxillary by esuthio
INDUSTRIAL by KIMJAEWOO FIREBRUSH
Adaptive Colossus-MtG, Brothers' War by Diego Gisbert Llorens
Magic The Gathering - Skitterbeam Battalion by Leon Tukker
A bit more of a fantasy vibe on this one, but it's extremely cool, and easy to see this same idea conceptualized in a more straightforward science fiction universe.
Old Shipyard -UE5- by Andrey Egorov
eclipse by esuthio
Roman Centurion by Steve Jang
