Since I don't know enough about the EU and I'm not that good at creating peculiar and interesting characters, I thought about giving it a shot from the optimization side, being quite the min-maxer.
So here, as my entry, I present
Mandalore the Optimized or how one can reach the top of the Mando'ade with careful choices in his training.
I'll provide a description and building explanations for each point of his long career, I hope you enjoy it.
Creation notesThis is by no means the very best armored-guy-with-rifle build, but I think it's pretty solid. Some choices were made to fit the style of a soldier improving his military expertise and to have a complete character at each step. Regarding the crunch I tried to incorporate most of the Mandalorian traits as provided in the manuals, but with little knowledge about the EU I preferred to use the Fetts as my paragons.
The build main feature is the Armored Mandalorian talent. I went for the Gunslinger/Elite Trooper/Officer chassis and kept the multiclassing at minimum.
I used PB 28, Human, avoided weapon specific feats and tried to stick to passive bonuses for the most part to make it easy to play, easy to use as NPC and highly customizable, expecially at the highest levels. 16 is the peak (12'd have been fine too) to mimic CLs of the Fetts and Mandalorian Supercommando.
Gear OverviewBasic possessions since level 1 are: blaster carbine, Mandalorian armor (as any of the +6/+2 light armors with helmet package and jetpack), utility belt. At level 16 he gets his proper Mandalorian armor with DR that applies to lightsabers
The above is more than enough for presenting the build, but I'll list some additional personalization (most rules are in S&V).
The ideal weapon would be a sporting blaster carbine with stun setting stripped plus rapid recyler and improved energy cell upgrades.
The ideal armor would be a Mandalorian version of radtrooper armor (+6/+4) with anything that increases its equipment bonus that'd add to his DR.
Armor upgrading is an ever changing process between battles, here I'll just suggest a couple of weapons that might have been added at some point by using integrated equipment upgrade, miniaturize, dual gear, attachment and tech specialist: grenade launcher, missile launcher, shock stick, flamethrower, stun pistol, whipcord, blaster gauntlet, dart launcher, melee weapon (the S-5 heavy blaster pistol has 3-4 of them combined into one weapon).
As a closing note I left out any starship he might have (instert Slave shameless copy) because I didn't want to add further gear or rule stuff and wanted the focus to be on the character itself.