Starting with GOG.com, you can get the best Settlers (II) and a not so good Settlers (Heritage of Kings) for $9.99: http://www.gog.com/en/promo/the_settlers

Then we've got the Impulse deals, where the main deal is probably Prince of Persia for $22.49 dollars: http://www.impulsedriven.com/

The GamersGate deals:

• Tropico Reloaded 50% off, for 7.50 http://www.gamersgate.com/DD-TROPR/tropico-reloaded
• Majesty 2 60% off, for $15.98 http://www.gamersgate.com/DD-MAJ2/majesty-2-the-fantasy-kingdom-sim
• Elven Legacy 50% off, for $15 http://www.gamersgate.com/DD-ELVEN/elven-legacy
• King's Bouny: The Legend 50% off, for $12.49 http://www.gamersgate.com/DD-KB/kings-bounty-the-legend

And finally, D2D:

Crayon Physics Deluxe 50% off: http://www.direct2drive.com/8673/product/Buy-Crayon-Physics-Deluxe-Download

interesting

There's also a Sango 2 + Takeda 3 bundle at GamersGate, basically you pay the price of one game for two.

http://www.gamersgate.com/DDB-S2T3/sango-2-and-takeda-3-bundle

there's a demo for each game available too:

Sango 2: http://demos.gamersgate.com/5761

Takeda 3: http://demos.gamersgate.com/5771

both games appear to be similar to the Total War games, and there aren't any reviews for them at GameRankings lol

Tropico and Majesty 2 looking really good value for money.