I'll start... (DISCLAIMER: These are my personal opinions!) 1. Highway Nights: In my honest opinion, this was the most refined game of them all. It had a real story to it, the car list was good and the map design was the best out of all the games. The day and night cycle was also a neat addition. 2. Burning Wheels: The first game to introduce free roam, it had the most diverse car list. The MadCop building part of the story was interesting and the parts for it were worth collecting. 3. Crash Time: It's definitely an upgrade from Nitro, though it still has its flaws. The maps are too small (I gotta admit, the sewers in the city were a nice addition), some missions are either unforgiving or are a bit confusing. The car list is good and this was the first game to have real dialogue, so that's a huge plus for the series. 4. The Syndicate: I wish I could place this above Burning Wheels and Crash Time, but for some reason, Synetic decided to throw out some of the things that made Highway Nights good. I wish they kept in the Instant Replay feature as well as the day and night cycle, but the game was plagued with performance issues and some ugly cars. The Cologne-based city was a nice touch, though I can't say the same for the Autobahn map. Two things that really put me off were the prisoner transport and surveillance camera thingy, I hated those. 5. Nitro: It was basically a story-driven version of World Racing 2, though the car list and maps were too small and the story could be beaten in just an hour or so. It wasn't a bad game, though. 6. Undercover: Oh, where to begin with this? This game threw just about everything out the window. The performance issues were worse, the cars looked uglier, the supercars were uninspiring, some good cars went away and worst of all, no city map and no free-roaming (the "wannago" cheat does not count). Don't get me started on the clunky weapon system, which was copied from NFS Hot Pursuit 2010, and the poor progression. Making circuit races that had no connection to the story mandatory was an absolute BAD idea. Seriously, what the hell was Synetic thinking? Couldn't they make it a separate mode for unlocking certain cars? 7. Crash Time 3D: Never played it and never will. I've seen gameplay videos of it and it looks crappy.