Just a thought I have had recently:
How would you rank what are generally considered the worst Ultima games in the series?

Here's the list:
* Ultima 2
* Ultima 8
* Ultima 9
* The NES version of Ultima 5

It's perhaps a good thing that you didn't play NES 5; it's *bad*. Not just "the game doesn't fit my tastes bad", not just "there are a few major annoyances" bad, but more like "the game should not have been released in this state" bad. For example, the game sometimes drops input, the only way to restore MP appears to be deathwarping, and there's only one music track that plays for the entire game (except the title screen, intro, and ending).

To give another example of how bad it is, I would compare it to games like ET and Big Rigs.

NES 3, 4, and SNES 6 are at least decent (NES 4 is actually better than other versions in some respects, but worse in others), but NES 5 just isn't.

There's a speedrun of Ultima 5 NES at:
https://www.youtube.com/watch?v=zlmrjx19p2c

(No, I am not the runner; I usually prefer to play games that are actually fun.)

I didn't get to play the original games in order of release, so some of the flaws of the games weren't so apparent. Therefore:

Ultima 8, 9 and 2.

Ultima 2 felt so disjointed from the rest of the series. Earth just felt odd. It was hard to believe it spanned the entire globe, the story felt so disjointed and the gameplay design was insane. Insane! The game is very difficult to play from start to finish without consulting a guide. You're expected to do things without any prompts. Things you're most likely not aware you can do. Also, coming from EGA (?) Ultima 1 remake to Ultima 2's CGA was a bit of a let down. But it's not so bad overall. Because the consistent design process becomes very apparent with Ultima 4 onwards. And so many PC games of the period were a lot like this.

Ultima 8 was the 2nd Ultima I played, after 4. I didn't appreciate the negative reviews as I didn't witness the transition from 7 to 8. Where fans were disappointed going from 7 to 8, I was rewarded by going from 8 to 7. It was a clunky game at times, but I was playing a totally patched game in 1997/8. So it worked.

Ultima 9 was such a disappointment after playing the entire series before its release. I followed the entirety of development, pre-ordered and was so excited to witness the release of a contemporary Ultima... and damn was I let down. The game was completely unplayable thanks to terrible performance and technical bugs. All the promises of a virtual world, with the same level of detail as Ultima 7 and Ultima online, was no-where to be found. I loved how the look of the world, the characters, terrain. props, etc., but the scale wasn't there. Britain felt like a big street compared to the scale of UO and 7. And the story? Well, what else can I say that others haven't' already said enough times over. I rank it above Ultima 2 because I consider it a better game, but we're comparing two very bad apples here...
Further to my last: I can't comment on the NES games as I've only played seconds of them. I'm not a console fan, at all, and have no interest in trying them. Default to the bottom of the list, I guess?

Ultima 2 is a good idea (introducing proto-moongates) but ultimately as a game it's a step back from 1. However I've only played the "EGA Enhanced" version of U1 you got in the Utlima Trilogy in the late 80s/ early 90s which I think was from the mid-80s on the only way to buy it... apparenly there was an "original" version without colour, possibly Apple only...

Ultima 8 was a massive let down fron Ultima 7. A total "WTF" moment even though I first played it YEARS after it came out. I was already a little uncomfortable about the dumbed down combat in the otherwise excellent U7 (real-time, not tactical turn-based, less control over party members) and about how U7 leaned more towards the adventure game side than a D&D simulator. U8 just completely hammered that home - an adventure game with platform jumping and no party. Doh!

Ultima 9 I feel very sorry for as its failures spelt the end of Origin. I really think people should try a fully patched GOG version and re-assess though - I got it some time after the original patches came out so experienced none of the early adopter problems other super-fans suffered from. While I didn't like the fact that the avatar had been reduced to some dumb Homer Simpson alpha male, once I mentally blocked that I actually found the game quite enjoyable and atmospheric to explore Britannia in full 3D. It pales in comparison to the best Ultimas, but it is actually not a bad game especially if you like puzzles in your dungeons!

I can confirm this. In addition, the background graphics weren't animated; for example, the ocean waves didn't appear to move.

The problem is 9 does more than make the Avatar into an idiot that makes Homer look like a genius ("The Codex of Ultimate Wisdom?" "What, I mean who, are the Gargoyles?", "What's a Paladin?"). It also makes other pointless changes/decisions that damage the setting and are even worse as the conclusion to the series. I once tortured myself with a playthrough that made it to just before the end that got lost in a computer failure. I can not bring myself to do it again, even with a patched version.

Having no party in U8 to me actually felt like an improvement over the clusterfuck that was combat in U7. Only one character also meant less annoying inventory management. It seemed to me back than, that Origin realized their bad design decisions in U7 and didn't change them, but tried to minimize their effects.

I think if they'd stuck to a more sedate turn-based system like U6, then U7 wouldn't have suffered so much from "Press C and keep your fingers crossed" combat. However, I am a fan of turn-based tactical combat so I'm always going to be biased in that direction. Inventory management is something I weirdly enjoy too... organising your stuff is a staple of RPGs!