Best armour

you could prolly just enchant a robe or something with shield, or get the three enchanted rings and necklaces with 33% shield and then your pretty much invincible to any physical damage.

Theres that helmet in the water but thats not that good. I saw my sisters boyfriend get it when he was playing Oblivion over here.

there are soem secret armours in the game, these are what I know of:

Crown of Lindi (requires completing the collector's missions, you find it in Lindi)
Crown of Nehata (same mission, its hidden in the imperial city though) both are light armour
Spellbreaker (shield with powerful reflect enchantment) from quest on one of the daedric shrines (its near the panther river)
saviour's hide (hicrine shrine quest, north of bravil near inn of ill omen) probably the best light armour in the game.
Fin Gleam, underwater near island near anvil, next to a skeleton (glass armour)
Brusef Amelion's Armor in the Amelion Family Tomb, near bravil (but its really crap even though it looks cool)
Helm of Oreyn Bearclaw (from fighter guild quest)
Umbra's Ebony armour is also unique, in vinsasal south of the imperail city near pells gate and the old bridge, thats all I can think of for now

Well, no, those are the strongest armors that you have. Umbras armor is a weaker version of ebony, so don't bother with it. Brusof Emelions, like he said, looked cool(its a pale blue ebony armor) but doesn't do that well. Then theres the Saviors Hide, which I have to admit is really good, but I think the Cuirass of the Crusader is better. Spell Breaker isn't really worth it, because I was able to get through the Mages Guild questline without it, so it can't be that great. Then theres the Esutchion of Chorrol, an altered ebony sheild. Its nice, but I think its got the same stats as a normal ebony shield.

And with all the stuff thats different with Oblvion from Morrowind, why would they have added in all the secret armor, lol...

my armor is best.
i got full daedric and all enchanted with feather by 125 points.
and i got full glass which is also enchanted with feather by 125 points and with my master skill in light armor i carry almost as much as i want.. awesome stuff

Tall, he said he enchanted BOTH daedric and glass. Not just daedric.