Cities XL Platinum is widely considered the "ultimate" but flawed version of the Cities XL series. While it offers a massive scale and detailed 3D graphics that allow you to zoom to street level, it is plagued by technical issues—most notably a memory leak and a lack of multi-core support that causes performance to crawl as cities grow.
Where to Find Free Mods: Here are some popular websites and forums where you can find free Cities XL Platinum mods: cities xl platinum mods free
Must-Have Mods: Experts on Simtropolis and XLNation strongly recommend not playing without community fixes. Cities XL Platinum is widely considered the "ultimate"