If you want to run a Battlemage set, perhaps wielding a sword in one hand and ferocious firebolts in the other, you can enchant it for buffs to Magicka regeneration and spell costs.
Although combat with swords, axes, warhammers, maces, shields, daggers, and bows is well-suited to standard armor, magic is a different kettle of fish. The one outlier in this situation is mages. However, if you see yourself as the latter, you’ll want to charge into battle wearing the most elephantine hunks of metal you can find. Are you an assassin-type, silently scouring the dimly-lit oubliettes buried far beneath dubious embassies? Or are you the kind of person to leap headfirst into the fray, wielding a walloping warhammer with wicked wisdom? If you tend to lean towards the former, you’ll want light armor, which will make your sneaking more effective and your stamina more manageable.
However, before deciding what the best Skyrim armor is for you, you’ll need to commit to a playstyle.