I keep a list. Here are some of the entries. All of them are fantastic. I'm especially addicted to Total Extreme Wrestling and Extreme Warfare Revenge.
SPORTS MANAGEMENT SIMS
Puresim Baseball
Once, you had to pay for it, but now it's free. One of the best baseball team management games ever. This thing simulates everything from games, coaching, finances, recruiting, draft, and pretty much everything you can think of in the day to day ownership of a professional baseball team. It's a fantastic sim, especially if you're a baseball fan. Just go to their "Older Games" area on their website and download it from there.
http://www.suldogstudios.com/
Lots of awesome addons, player pictures, and ball parks can be downloaded from here:
http://web.mac.com/sixwilsons/PureSimMods/Main.html
UFL
A Football Management sim written in visual basic. You can either play this thing as a game, or you can use it to simply manage your virtual football league. It's not pretty to look at, but it's really well done and has quite a few options.
http://ufl.no-ip.info/
Secondary page with Documentation and a forum:
http://ufl.50megs.com/index.htm
Extreme Warfare Revenge (EWR)
A really fun professional wrestling promotion simulator that I play all the time.
http://www.ewbattleground.com/
Modern, up to the month database update can be found here:
http://www.ewbattleground.com/forum/index.php?showforum=5
Picture packs and historical and fantasty database updates as well as utilities can be found here:
http://ewr.host22.com/
and also here:
http://www.ewinventory.com/ew.html
Total Extreme Wrestling 2005 (TEW2005)
The sequel to Extreme Warfare Revenge. More complex, but it has MULTIPLAYER !!!
http://www.ewbattleground.com/
The forum can be found here:
http://www.ewbattleground.com/forum/index.php?showforum=4
If you go into the TEW forum, the monthly real world stat update can be found usually at the top of the list.
Picture Packs, historical, and fantasy databases are here:
http://www.ewinventory.com/
The best picture pack for use in either EWR or TEW2005
http://www.megaupload.com/?d=F691NXBC
Another excellent site for mods, pics, and scenarios for TEW2005
http://bobinc.net/TEW05Downloads.html
If you want any updates that you can't find, ask me. I have them ALL.
5th Generation Wrestling Simulator (5GWS)
Another good wrestling promotion simulator. Although it's dated, it's still fun to play. The next version is coming out within the next few months and it looks incredible. You can download 5GWS and it's database update here. Just sign up for their forum and go to the "downloads" area.
http://www.blackdragongames.co.uk/
Ultimate MMA Simulator 2
I'm impressed with this Ultimate fighting simulator. It has an extensive database of real world organizations and fighter and delivers pretty realistic results. It also includes editors allowing you to alter or add whatever content you wish.
http://www.blackdragongames.co.uk/
Stellar College Basketball
College basketball sim with all the teams. There are also addons available that give you all the best all time players as well.
http://www.stellarcollegebballgame.com/
TRAIN SIMULATORS
Open BVE
Open BVE is a train simulator. It, like Orbiter has a large following. There are lots of trains, train routs, and scenery to download for it. It's very well done. Driving a train is a lot more challenging than you would think.
http://openbve.trainsimcentral.co.uk/
SimSig
Who would have thought that such a thing can be so fun and challenging ? SimSig is a train signal operation simulator that puts you in control of the signal controls for an entire railway. It actually can get pretty hectic and it's fun ! There are also extra routs to download for it. It also supports multiplayer.
http://www.simsig.co.uk/
DRIVING SIMULATORS
Motorsport
A cool driving sim with a lot of cars and maps to download. The aim of this project is to create the most accurate driving experience ever done.
http://www.motorsport-sim.org/
TORCS
TORCS is a car racing simulator. It simulates track racing like NASCAR, and Formula 1, etc.. stuff. There are many tracks and cars to download for it and it has multiplayer capabilities.
http://torcs.sourceforge.net/
Racer
Racer is another race car simulator. It's still in Beta, but it looks promising. My computer has a hard time running it.
http://www.racer.nl/
VDrift
Another racing sim. This one however focuses on the ultra-light drifting style of racing. It's a LOT of fun sliding your car sideways at 80mph through every turn.
http://vdrift.net/
POLITICAL SIMULATORS
Conflict: Middle East Political Simulator (The Remake)
This is a fan remake of the still playable classic that is long out of production. The remake is excellently done and has enhanced graphics and more options than the original. In this game, you are the newly elected prime minister of Israel and you have to deal with the day to day political climate and events of the Middle East with the goal of being re-elected. The random nature and realism of this game create an addictive and endlessly re-playable experience.
http://ilfera.blogspot.com/2009/02/end.html
BUSINESS SIMULATORS
Informatist
Informatist is a fun, massively multiplayer business simulator. You invest in stocks, strike deals and do hostile takeovers of other companies, and handle the day to day business of your company. Considering the fact that every company is run by another player, the possibilities and replayablity of this sim is endless. The accuracy of it's online stock market and business models are reasons that actual business students and classes use this game as a learning tool. It's really fun to rack up millions and millions of dollars (I wish it was real).
http://www.informatist.net/
