basically anything that's a bit secret.have 360 oblivion and completed the main quest (fighters/mage's guild questline also).have found fin gleam.will be getting 5th anniversary when released in uk (so will have kotn/shivering isles). i did find the chapel of the monks (something moths) which i was pleased to discover (there were a lot of blind monk warriors in the basemant caverns).thanks in advance.
Ah yes, the Moth Priests. Keepers and diviners of The Elder Scrolls. Made blind by reading the prophesies. My single most anticipated moment when I installed Oblivion was to find them.
Anyways, here is a page on http://www.uesp.net/wiki/Oblivion:Easter_Eggs
As far as side quests, I enjoyed;
http://www.uesp.net/wiki/Oblivion:Lich_of_Lost_Boy_Cavern
http://www.uesp.net/wiki/Oblivion:The_Sirens_Deception
http://www.uesp.net/wiki/Oblivion:The_Forlorn_Watchman_(quest)
http://www.uesp.net/wiki/Oblivion:Secrets_of_the_Ayleids
http://www.uesp.net/wiki/Oblivion:Ghost_Ship_of_Anvil
http://www.uesp.net/wiki/Oblivion:A_Brush_With_Death
http://www.uesp.net/wiki/Oblivion:A_Shadow_over_Hackdirt
http://www.uesp.net/wiki/Oblivion:Mazoga_the_Orc_(quest) *ahem* I mean,
Sir Mazoga
http://www.uesp.net/wiki/Oblivion:Paranoia
http://www.uesp.net/wiki/Oblivion:Where_Spirits_Have_Lease (and gain a respectable home in Anvil)
http://www.uesp.net/wiki/Oblivion:An_Unexpected_Voyage
Actually I could keep going. I enjoyed the side quests more so than the guilds and MQ.