Okay, here's the answer the grand Episode #58 Ultima question.
You can get almost all of the Ultima Series on GoG.com at the following links:
Ultima 1, 2, and 3: $5.99
Ultima 4, 5, and 6: $5.99
Ultima 4: FREE
Story-wise: 1 and 2 are pretty fucked up. And not really in a good way. 3 is where things started to get sorted out into a "good" story. 4 is the prime meat of story begins. And it only gets better from there. Keep in mind, each of these games pick up the story almost right where you left off from the previous game, and you could even load your character data from the previous game to continue onward. (i.e. Install Ultima 6, load savegame data from Ultima 5)
Graphics-wise: It's really old PC shit, and isn't good until Ultima 6. And Juese, the SNES port of "Ultima 6: The False Prophet" is the one that's almost 99% true to the original PC version. If anything, I really like the SNES way of playing it. And it's somewhat rare, too.
But the game that brought all of the Ultima collective storylines together and went for awesome was so long, they decided to split it into two separate games. And they are Ultima 7: The Black Gate and Ultima 7: Serpent Isle. We're talking classic isometric view RPG goodness here. These two games combined took me over 3 years to finally complete in their entirety. The bitch of it is, to run in their original forms is a pain in the ass on a modern system. The SNES "port" of this is so completely and utterly butchered, it looks like it came out of a pig's ass.
Enter
Exult. An open-source "engine" of sorts. A bunch of nerds got together and completely reversed-engineered the original gamefiles, and made it possible to play these awesome games together on Windows, Mac, Linux, and I shit you not, I can play this quite well on my Android phone. (Fuck yeah, slide-out keyboard)
However, you still need to own a copy of the original gamefiles themselves to be used with Exult. I recommend finding a copy of the "Ultima Collection" on Goozex, or even Amazon. This collection includes "Akalabeth" a.k.a "Ultima 0". (It's REALLY OLD. End of story) Also, it has Ultima 8: Pagan.
HUGE NOTE: I will help anyone install and configure to play these games on pretty much anything. Shoot me a private message, and we'll talk.
Ultima 8 is the attempt at a Super Mario Brothers game. It's an alright game, but it's a radical departure from the rest of the classic gameplay with companions.
Ultima 9 is an abortion of a game. Richard Garriott had no hand in making it. It fucking sucks.
I'm a bigger X-Strike fan than you.