Do eny one know other (Unique items or items who loocks unique)and this,
(not artifacts):

1Blackwater Blade
2 Blade of Woe
3 Burz's Glass Mace
4 Chillrend
5 Debaser
6 Hatreds Heart
7 Hatreds Soul
8 Mishaxhi's Cleaver
9 Northwind
10 Redwave
11 Rockshatter
12 Shadowhunt
13 Sufferthorn
14 Thornblade
15 Witsplinter
16 Apron of Adroitness
17 Ayleid Crown of Lindai
18 Ayleid Crown of Nenalata
19Bloodworm Helm
20Boots of Bloody Bounding
21 Escutcheon of Chorrol
22 Kvatch Cuirass
23 Valdemar's Shield

Here is another list:

http://www.uesp.net/wiki/Oblivion:Unique_Items

Not sure if it is complete though.

Hmm,I have seen that Nett S. before.

P.S. But thx anyway

erm... not sure about this, but

circlet of omnipotence(+3 to lots of attributes), ring of war(+10 to lots of skills)

Boreal (a glass claymore)

you can get the Blade of Woe by murdering someone. After that sleep in a bed and a man from the dark brother hood should come. Talk to him and he will give u the Blade

Fin Gleam
hard to find, but it has water breathing and night eye

What about the Weatherweld Circlet?

You get it after completing the Grave-robbing quest in the Imperial City.