It took me a year to build up my courage, but I finally returned to the realm of Oblivion. I think that I had spent so much time and effort on the main part of the game that I was a bit afraid of what would happen to the remainder of my schedule if I plunged onward. And I had a feeling that the prices would continue to fall if I waited longer. I was right on both counts. While the expanded content doesn't take up as much time as the main game, it is longer than, say, the main quest by itself. It is good, a bit less focused than I would ordinarily like, but sprawl has always been a significant part of the appeal of The Elder Scrolls.
These days, you typically get the add-ons in two parts. First up is a package that contains the Knights of the Nine and a whole host of tiny mods. The mods have very little quest content, but do add some cool new parts to the game. Many of these are related to strongholds - each associated with a particular character type (a pirate ship for thieving, a mystic citadel for mages, a cultish crypt for assassins, etc.), each requiring very little quest work to obtain, and costing a whole lot of money to buy all the upgrades. The production quality is excellent - the art and design feels top-notch for all of these. Once you have them, they're interesting but not essential... it's good to have another place to stash your stuff, and the mage tower is particularly useful, but for the most part you need to visit every week or so in order to get the maximum benefit, and as a result most players probably won't get a whole lot out of it.
That does bring up a good point: while most people will be playing (who am I kidding? have played) these after the main quest, they can be installed and accessed at any time. The strongholds in particular are probably most useful if you can do them at the very beginning of the game; you won't be able to fully unlock them until you get a lot more cash much later on, but that will still happen in plenty of time to take fuller advantage of them.
The main quest in this first add-on is the actual Knights of the Nine quest. It isn't directly related to the Oblivion story, but is connected to the same mythological background. It has a holy grail-ish aspect to it, and several interesting interleaving quests, nothing groundbreaking but all pretty solid.
I did like the way the story of the Knights slowly reveals itself as you continue. The treacherous knight in particular was an interesting character; I liked the way they handled him and the final resolution. The overall arc did feel just a little bit silly, though I think I may be getting jaded and this was one too many iterations of "An Ancient and Unstoppable Evil Is Awakening And Only You Can Stop It" for me. I did love the final set of battle sequences... the first time I was in the underground part near the end, I kept on killing the enemies, and getting increasingly desperate while the knights died one by one. I eventually went stealth, scooted forward, and found the crystal. Then I reloaded, ran past all the enemies, touched it and froze time. Very cool effect.
Mehrunes Razor is a cool weapon you can get. Mehrunes Dagon has always struck me as one of the most menacing Daedra, so anything connected with him immediately fascinates me. For a long time I stashed the Razor in Bruma with all the rest of my magic stuff. I may have complained about this before, but since I didn't take Armorer as a primary skill, it took me FOREVER to get it up to 50, which sucks since you can't repair magic gear until it's that high. So, even though I had tons and tons of cool magic stuff, I just wasn't able to take advantage of them... instead I would use the best generic armor I had (eventually elven), while salivating at the thought of one day being able to cart around my arsenal.
Anyways. After I FINALLY got up to 50, a long long time after I beat the game itself, I went on a shopping binge in my own Bruma closet. I ended up picking the Razor as my blade, as much for its extreme light weight as for anything else. I think that by the time I beat the game I had only claimed, like, five souls or so. It did make me curious if there's any advantage to claiming souls, if it actually grows stronger in power like, say, the cool day/night blade you can get in Shivering Isles. Oh, if only there was some sort of Internet where I could gather information on these kinds of things!
All in all, Knights of the Nine is worth checking out at its now extremely discounted price. If you get the game of the year pack, you'll get everything with it, which is nice.
The big add-on, though, is Shivering Isles. This actually has a new binary and, much to my anger, strong copy protection. It didn't want to play with Wine, so I had to take drastic measures to make it run. Darn you, publishers! Why must you make it so difficult for people to play their legally purchased content!
I've been fascinated by Shivering Isles ever since I heard the premise, and it largely lived up to its promise. The Shivering Isles are the realm of Sheogorath, the Daedric lord of madness. The entire realm is one of madness, filled with crazy people, bizarre monsters, the Fork of Horripilation, incredibly colorful terrain, oddities of all sorts. Best of all, you get to interact with Sheogorath himself, and gradually take on more and more of the attributes of Madness yourself.
The game felt kind of like a mini-Oblivion without any guild quests. There's still a massive map, with lots of places to explore, and content that you won't cross unless you happen to wander. The main quest is interesting, and every village you cross has a couple of fun things to do inside it. There's even a new set of lore to absorb - besides classics like "The Madness of Pelegasius" (sp?) they have many more books on insane topics, steeping you in the contradictory history of the realm.
Most of the voice acting is kind of annoying, but Sheogorath himself is fun. He slips in and out of a Scottish accent, changes mood halfway through a sentence, sends you on missions and then mocks you when you return. I also liked his chamberlain, Haskill, whose dryness and drollness is a perfect counterpart to the manic character of Sheogorath. In contrast to most of the rest of the game, I usually let their dialog play out fully instead of clicking through.
The actual rewards at the end are fun, though I will almost certainly never take advantage of them. You become the God of Madness yourself, and while this does almost nothing in other realms, you can wield considerable power within the Shivering Isles. The niftiest power is the ability to change the weather on your whim. You can also summon a dancer to perform for you. She... well, I guess she's as good as a 3D rendered RPG dancer can be. OK, maybe not, but still - YOU try programming someone to dance, it ain't easy. There's also a "defend your realm" thing going on, which I haven't had to do yet and probably never will.
Oh, yeah, the Graymarch. The resolution was pretty cool, except that it was obvious way too early what was going to happen... it was clear pretty early on that Sheogorath and Jyggalag were the same person. I wasn't disappointed or anything, but not exactly excited either. It WAS kind of funny that Mehrunes Razor worked on Jyggalag - I just had to stab him a few times to make him fall.
Besides the two official expansions, I also tried to run the most popular user-created mod, The Lost Spires. This sounds fascinating, but unfortunately, I could never get it to work - I could do the first few sections, where you can join the Guild of Archaeologists and meet the other members, but the game would always crash when I tried to enter a particular dungeon. Seems like a Wine compatibility thing. I don't think it's the engine itself that's a problem - I actually was surprised by how stable everything else ran under Wine - and I continued to have problems even if I unloaded or re-ordered my other mods, so it looked like some specific interaction that was causing problems.
Which is a shame - I've gotten so much pleasure out of Fall from Heaven 2, and had hoped that the Lost Spires would offer a similar expansively awesome experience. On the other hand, considering how much time I've already devoted to Oblivion and FfH2, they are probably doing me a favor!