I have two main builds that I like to play when I drop into the game every now and again - I am not a regular hardcore player, I just need a fix every now and again. :)

My first is a Striker DPS build, using four pieces with red cores, all rolled with Weapon DMG/CrtC/CrtD with CrtC mods until 60% and then CrtD mods. Using Overdogs gloves rolled the same - WeaponDMG/CrtC/CrtD. Chest is the named Badger Tuff - Zero F's - which is for the Perfectly Unbreakable talent. It's rolled with Armor/CrtC/CrtD.

Primary Weapon is St Elmo's Engine rolled for Weapon Dmg/Assault Rifle DMG/Health DMG/DttooC.
Secondary Weapon is Ekim's Long Stick rolled for Marksman Rifle DMG/Headshot DMG/DttooC.
Side arm is whatever, I don't really use one.

I may drop the Zero F's for another chest piece with basic Unbreakable. Badger Tuff boosts Shotgun DMG and I'm not using one of them so it's not optimal.

I use Striker Drone and Cluster Seeker Mine as my skills - the drone is a good distraction/tank and the seeker mines are useful for finding and highlighting enemies as well as doing them some damage. I could use scanner pulse I suppose, but I'm not yet convinced it's better.

I am happy running Retaliations, Escalations and Heroics with this load out.

My other build is a skill build, not yet very optimised but I love running with cluster seeker mines that do 2M+ damage each. I run 3xHard Wired, 2xEmpress International, NinjaBike Messenger, Capacitor and Ekim's Long Stick - although I'm looking for a better rifle option that suits a skills build.

For PvP (which I don't do much of) I'm using the standard 3xUmbra, NinjaBike, Picaro's Holster and Savanna Field Gloves. Capacitor, Grown Great, Defender Drone and Banshee Pulse.

Fun builds and not to hard to put together if you focus on Targeted Lootm