These topic trains are becoming pretty common. Two recent topics about very similar subjects:
http://www.gamesas.com/index.php?/topic/1202755-also-new-to-oblivion-pc/
EDIT: Information seems to get lost when you ask people to traverse multiple links, so quoted my replies to the other two.
EDIT 2:
For just basic companions there's stuff like http://www.tesnexus.com/downloads/file.php?id=3066t and http://www.tesnexus.com/downloads/file.php?id=7819
http://www.tesnexus.com/downloads/file.php?id=34576
Similar topic over at Planet elder scrolls:
http://forumplanet.gamespy.com/oblivion_plugins_mods/b49687/20744140/p1/?1
http://www.tesnexus.com/downloads/advancedsearch.php:
Friendship has 3 pages
Social has 6
Romance has 41 (some are probably nec
romancer type mods)
relation has 9
persuasion has 6
personality has 40.
Shouldn't be too hard to browse through some of those in addition to the ones in the other topic.
Personal recommendations:For a romance:
http://www.moddb.com/mods/integration-the-stranded-light
For a friendship/companion type stuff:
http://www.tesnexus.com/downloads/file.php?id=28977
http://www.tesnexus.com/modules/members/index.php?id=125368
http://www.tesnexus.com/modules/members/index.php?id=125368
http://www.tesnexus.com/modules/members/index.php?id=125368.Generic copy/paste for these topics. Answer some of the questions in the copy/paste and give some more details and we'll probably be able to help you more if need be.
Also be sure to not get overwhelmed and follow the basic rules.
Go slow
install mods one at a time
Install mods that are well known, and known to be stable. If you really like how an unknown mod made by a first time modder looks go ahead and install it, but be very wary
Get the basic utilities and learn their basic functions: Wrye bash, OBMM, BOSS, OBSE, etc.
Don't get caught in the peer pressure, and advertising of it all. Do some research of your own and get what
you want
etc.
Spoiler
For the occasional "What are your must haves?"
Plenty of romance mods that have marrying components. Personally I'm not a fan of the "romance and marry any NPC" type mods because they're basically the same as the mods that make things more "realistic" by crowding town and roads with generic, lifeless, robotic NPCs that serve no purpose, and have no personality.
Integration: The Stranded Light has a good romance with a certain character, most of the other romance mods are pretty campy, short, and unrealistic though.
As for what you asked:
http://www.tesnexus.com/downloads/advancedsearch.php
Description contains:
first try:
Marry
Then try:
marriage
Both of them have some pretty solid results, one of them has to be the mod you heard of.