So in my last post, I noted that I play a lot of solo Ingenious, PR, and St. Petersburg. In addition to these, I also play a bit of San Juan, Samurai, Taj Mahal, Go and Formula De. Samurai is a pretty decent adaptation, but the company that did it apparently folded before I could purchase a license to unlock the game. The demo is supposed to expire after 5 plays, but there is a registry modification that will reset this, so I can play as much as I like - what I really wanted to purchase this was for the alternate maps that the game included. Oh well. I actually prefer Samurai against real people, and since I can easily find a game on MaBiWeb, I tend not to play much solo. San Juan is a decent program, except that its painfully slow for the CPU to take its turns (and like PR, if you accidentally choose the wrong role, you are screwed - no take backs). Due to its slowness, I almost never play this despite my enjoying the real game. With PR on my computer, I may never play SJ again on my computer. Taj Mahal is a decent adaptation of the real game, except the thing that I think makes the real game tense is the "bluffing" against real people. It does play quickly though and is good practice for a game that isn't that intuitive out of the box. The author of Taj Mahal also wrote a solo version of Tycoon, which I have not tried. There are a load of Go games out there, I found one that is pretty easy to jump into and play, but I suck at the game - it seems to be a game that require I put in more time than I want. If I had someone to play Go with live, I might practice more. Its a lot like chess as far as that goes - good game, but I just don't have the time or willingness to "figure" it out. As for Formula De, FD on the computer is my preferred way to play this game. I really want to like FD, but the real game is just too damn slow. Why? Because its not easy to count out and see where your cars can possibly go. With the computer version, you click on a die and see exactly where you could land, then you roll and again - see exactly where you can move. Each turn takes about 15 seconds as opposed to 5+ minutes. Someday, I'll get this hooked up to a projector and get an 8 player game going and everyone will have a good time in about 2 hours instead of 5. I'd play this one a lot more too, but this is a game that I think is really best against a large number of real people.
In addition to those games, there are a number of games that are available for solo play on the net. Matthew Marquand has solo versions of Ingenious, Clans, and Coloretto on marquand.net. I haven't played Clans, but the versions of Ingenious and Coloretto are fun. The only reason I really wanted the new version of Ingenious was to play it online (which I have yet to do). I know there are some other site and downloads out there, I just haven't tried them yet. I found a simple version of Acquire out there at one point, but it didn't interest me enough to keep playing (though I like the game itself a fair amount). There are a bazillion versions of "classic" games like Risk available. Most big game sites like Microsoft's the Zone or Yahoo! games offer solo-playable classic games like checkers, backgammon, cribbage, etc.
Its worth mentioning that Days of Wonder offers a number of games including the excellent Ticket to Ride online. Its been a long time since I've checked it out, but you used to be able to play for free (with a few caveats). This was a very well done version that was a load of fun to play solo.
Finally, I also found some old computer games of boardgames at abandonware.com - 1830, Heroquest and Advanced Civ. These are all the original commercial releases of these boardgames that were done back in the days of DOS. I grabbed copies to see if I can't force myself to try these out and learn the games. I'm not real sure I'd ever sit down to play a real game of 1830 or Advanced Civ, but having tried them might help the cause. I also have an unopened copy of Age of Imperialism! (both the real game and the computer version) sitting around my office. Most of the knocks on this game deal with flaws in the boardgame itself, so I'm not sure that the computer version will make it any better - thus the reason I haven't tried it.
On the list of games that I wish there were computer versions of so I could play solo: Age of Empire III, Die Macher, Arkham Horror, Nexus Ops, Antike (heck, the more I sit and think about it, I'd probably play most of my games on the computer with the exception of pure auction games like Ra, Modern Art, Princes of Florence, Power Grid, etc).