I've been playing around with stuff, just leveling up different warframes and weapons off and on since the game came out. Last week, I decided to actually devote myself to one set of equipment to see how powerful I can get. I don't know why I didn't do this sooner. Now, I'm having a lot more fun and I've gotten powerful enough that it feels like I've broken the game.

Essentially, my main strategy is to cast Bastille to bring the entire room to a stand-still and bomb everything with Penta, using Galantine for cleanup or whenever something gets too close

Vauban (pure Bastille build)

• Energy Siphon
• Bastille
• Overextended
• Blind Rage
• Intensify
• Flow
• Streamline
• Redirection
• Stretch
• Continuity
• Constitution

Penta (max damage, experimenting with best elimental order, subject to change once I get my Tethra mods for status chance over pure power)

• Serration
• Heavy Calibur
• Split Chamber
• Firestorm
• Infected Clip
• Cryo Rounds
• Stormbringer
• Hellfire

I haven't forma'd a secondary yet (this is where I'd put Despair...IF I HAD ONE)

Galantine (obviously going for max charge DPS, again experimenting with elemental combos, but blast seems the best for close range)

• Corrupt Charge
• Killing Blow
• Reflex Coil
• Rending Strike
• True Steel
• Molten Impact
• North Wind
• Focus Energy

also boring sentinel stuff (running with Wyrm)

I've been meaning to reply to you, as I think it's an interesting topic. It's just a pretty complex answer (and I can't access the details of my builds at the moment :| )

That said, as someone currently at Rank 13, with all Warframes (except for Rhino Prime and Hydroid) at max-rank, many which are multiple forma'd, picking a main is... difficult.

I do believe that my most-played Warframe is still Rhino. Built mostly for general survival - all skills except for Rhino charge.

Other than that, I've got a Blessing-built Trinity built for Duration and efficiency (still need to find Natural Talent though... :/). Nova built for power strength and range. Frost Prime build for power range and Nyx built for range and efficency (with short duration) for Chaos-goodness. But I'll pull out any warframe people ask for for a mission.

I believe that most people in the clan still identify me as a white/purple Excalibur Prime (flexible take-all-comers-build) :P

As for weapons - Brakk is my only real "go to" weapon, using the standard build from dpsframe.com, minus Expel replaced with Quickdraw.

From experimentation yesterday, Nikana Dragon may become my go to melee weapon - had a lot more fun with it than I've had with any other melee weapon since 2.0. But I still need to find the stance for it, farming yesterday did not result in much.

And Carrier is the only Sentinel I care for. Didn't think they'd manage to replace Deathcube, but a sentinel that allows me to be lazy is going to win any day, I guess! :P (unfortunately Helios is too dumb and slow to be useful - and I've not gotten into the whole codex thing very much yet)

I've had an idea to trick out a standard, default appearance Excalibur, using tricked out, default appearance Braton, Lato and Skana as well for the humor it could result in... but not gotten far with those plans :P

I don't have a lot of fancy mods yet, so my loadouts are probably fairly vanilla. My main is a Nova, with a Nyx as a backup. Most exotic thing I have on them is probably Quick Thinking, which is nice in tight spots, especially No Shields nightmare mode.

Primary is a critical/damage focused Soma, which effortlessly tears through just about anything that isn't a boss or defense/survival 15+ minute/wave heavy. It's also got great range which is nice since I tend to end up on teams with a lot of Pentas and Phages. Most exotic thing on them is probably Hammer Shot. And, well, the Tethra's Doom electricity mod.

Haven't really done much with my secondary yet, and the melee weapons are Dual Zorens I'm planning on building for criticals when I have spare credits and fusion cores.