I love the Dark Brotherhood, probably because I gravitate toward Rogue-type characters. They always seem like the hardest but most rewarding characters to build.
My most successful builds in Fallout NV, however, have been unarmed and melee. There is something very satisfying about power fisting someone (don't take this out of context).
My favorite builds by game:
Oblivion- Female Wood Elf thief (Stealth/Archery - Thieves Guild)
Skyrim- Male Imperial Battlemage (Destruction Magic/Heavy Armor/One-handed - College of Winterhold/Empire)
Fallout 3- Female Sniper (Stealth/Small Guns - Neutral Karma sided with BOS)
New Vegas- Male Scientist (Energy Weapons/explosives - Sided with Mr. House)
Fallout 4- Female Charmer/Scientist (Stealth/Balanced with ranged weapons - Sided with Institute)
I have wasted a lot more time in skyrim than you have
I ran out of things to explore, which is kinda weird if you think about it if you compare it with the other games.