I'd go with thief personally, a glass cannon at the start but when you start to get the gear/skills/perks you'll become a tank&spanker.
Good early build is to get second wind, fade away, crushing blow and spring attack, rotation would be spring -> crush -> spring -> crush until you start to lose your footing/stamina, then use fade away and second wind, after regaining stamina/footing, spring -> crush -> spring -> crush, rinse and repeat till the enemy is defeated.
Perks should also focus around this, getting stability and sunder perks and other melee perks, then also picking some of the stat perks like str/end/agi/per to succeed some checks (charisma for some is necessary).