Hi,
I tried the OOO mod but didn't really enjoy it, mainly because they make skills less powerful; my level 36 character for example, had the power of a level 5, not good imo.
I don't recall where I got my mods from, there was a torrent release around a while ago, all the fan made add-ons in one place, but I only use the following now:
attack and hide harder v2.1.esp - think this makes people only search for you for a short period, I don't recall much more tbh.
Deadlier Sneaking 1.1.esp - handy if you play the game Thief style, like me, as this gives more damage for stealth kills iirc.
Deadlier Traps.esp - makes looting ruins a little more dangerous.
FathisFix.esp - Fixes a stupid bug in the game, although my have been fixed by the last patch.
mighty_bows_arrows_recovery.esp - allows you to recover more arrows from those you kill.
MM_NoMoreAnnoyingMessages.esp - hides some of the on-screen messages that aren't really needed.
No persistant enchantment glow fix.esp - just something for looks, enchanted kit doesn't glow 24/7.
No psychic guards v1.2.esp - - fixes the issue with guards, like Psypher5 says.
Short Grass V2.esp - helps boost performance by repalcing the grass with a shorter version.
TF_timemod1-20.esp - slows down the time compression I think.
town loot v1.0.esp - more things to nick
Valuable Art.esp - same.
Wineman.esp - not found this guy yet, but you can buy wine from him.... handy for drunks I guess.
Scort.