Well, after watching a video of the history of the Need For Speed series, I think I'll give my opinion on the games of the series. What I like, what I don't like, stuff like that.
(Wall of text ahead, sorry!)
The Need For Speed (1994): The one that started it all. The concept still makes sense today: racing exotic cars on open roads. Guiding your Viper down the coastal highway, trying to stay ahead of that Porsche and the cop in your rear-view mirror. It would still be as much fun today. Partnering up with Road & Track magazine didn't seem to hurt either.
Need For Speed II (1997): It wasn't such a high point for me, even though I didn't play it. Yes, it was more advanced and featured several exotic and concept cars, but I feel that without the addition of police, it felt like another racing game.
Need For Speed III: Hot Pursuit (1998): Unlike the first two games, I did get to play this one, and it's one of the best for me. It went back to the old formula of exotics racing and chasing. The tracks were excellent and the cops gave you a challenge like never before. On the PC version, you could even get behind the wheel of a police cruiser, and I used to love nothing more than getting in the Police Corvette and rocketing off after speeders. I'd still love to play that game...
Need For Speed: High Stakes (1999): I didn't play this one, but it seems like an improvement on NFS3. I mean, just take a look at this: damage, more cars, more advanced pursuits, more tracks and even pink slip racing. If it's an improvement of even NFS3, it seems good enough to me.
Need For Speed: Porsche Unleashed (2000): A game featuring only Porsches... It's such a good game. It's fascinating to go through the history of Porsche, see the cars they used to make and get to drive them. It's like a Porsche version of Gran Turismo, and very similar to Mercedes-Benz World Racing that came out a couple of years later. I still think there's potential for this kind of game today. See my signature...
Need For Speed: Hot Pursuit II (2002): A spiritual successor to NFS3, and with all the things that made that game great. Exotic cars, big tracks, and cops that had the means and the motivation to stop you. Also, the last of the series before NFS started going down the route of the TFATF street racing. I still have a PS2 somewhere, with copies of this, U2, MW, NFSC and UC. And you know what? I still like to play this game. Truly great.
Need For Speed: Underground (2003): To be honest, I don't like this game as much. Yes, I did play it a lot in the past, but I felt it was cashing in on the TFATF tuner hype, and this kind of midnight street racing with wild customization didn't really appeal to me...
Need For Speed: Underground 2 (2004): ...And this one just took it to the next level. OK, so I admit, there are people who liked this game, with the highest amount of customization ever seen on an NFS game, but what I didn't like was that I HAD to modify my car to progress through the game. Me, I personally like to keep a stock and/or purposeful appearance, so sorry guys, this didn't really float my boat. Also, I am really getting fed up with people asking, shouting, begging for an Underground 3. Why? Just read this again...
Need For Speed: Most Wanted (2005): One of the best games of the series IMO. One cannot mention Most Wanted without also mentioning the police system, and this game had a fantastic police system. It really gave you a challenge, and the cops adapted as you ran from them more and more. This pursuit system went on to be used in Carbon and Undercover (with a few modifications). Customization was back, but it was toned down and wasn't an essential part of the game any more. This appealed to me: I was able to keep a stock appearance, just customizing my car to keep it from gathering too much police attention. This game was simply amazing.
Need For Speed: Carbon (2006): Some might call this worse than Most Wanted, but I think it's just as great. Crew racing was interesting, sending your blocker to take out the leader or ordering your drafter into action on the long straight was important to success. The turf wars was also rather interesting, as you fought for control of the streets. Palmont was the warzone, your crew was the army, and your car was your weapon. Canyon racing was the real deal, a place where it was tricky to pull out a lead, and going over meant it was over. Some might deem it an expansion pack of Most Wanted, but I think it's more than that.
Need For Speed: Pro Street (2007): Taking a turn towards the more legal kind of racing might not have been the smartest move, but I still like PS a bit. The customization is now about functionality, and the car list was nice and varied. Not to mention, you can still get an adrenaline rush trying to keep your car in control at 200MPH on Nevada and trying not to go off the road and out of the race.
Need For Speed: Undercover (2008): I got to play the PS2 and PS3 versions of this. The PS2 version kinda seems like a modified MW, but it's still unique. The PS3 version is the proper one. OK, so the physics were a little tricky and I'm not sure if the story line appeals to everyone. And yes, there are a few bugs in there. Overall though, I feel no shame in saying I liked Undercover.
Need For Speed: Shift (2009) and Shift 2 Unleashed (2011): These games had the bold idea of taking on Gran Turismo at its own game. Not sure how much of a success that was, but the result was good. IMO, S2U had more for me than NFS:S. Ready? Drag racing, engine swaps (with certain limits), more cars, old cars, more tracks, less floaty physics, GT3 and GT1 racing and more. I still play S2U, it helps me live my drag racing, engine swapping, 1000HP tuning fantasies that I can't do on GT5.
Need For Speed: World (2010): They had a good idea here: A Need For Speed like Most Wanted and Carbon, set in those cities and which you can experience in a TDU-like multiplayer experience with other players. But I never really picked this up. Internet download? I'm a little paranoid of those. Maybe I would've got it if if was on a disc. Now, looking back, I'm glad I didn't get it. What with all this Speedboost content, it's not exactly Free-To-Play, isn't it? I mean, you could go through the game without spending anything that's not in-game currency, but there's so much paid-for content, and it seems like you have to pay to get the good/competitive stuff. Also, there seems to be a BIG cheater problem, a problem that the new achievements seems to have encouraged. Now Quicklime has been shut down, it seems like this ship may have been abandoned.
Need For Speed: Hot Pursuit (2010): I liked this game. I liked it a lot. Returning the focus to police chases, this game had some of the original spirit of exotic road racing, with a bit of 21st century injection of drifting and weapons. The drifting was a little overused to me, but overall I liked this game, especially for the fact that I could be a cop once again. I used to play this game ALL the time in 2011.
Need For Speed: The Run (2011): Another good idea: Man on the run enters cross-country race to save his life. The result? Kinda disappointed me. There were a lot of cars, but the levels didn't feel connected enough for me, and were a little repetitive. This game REALLY needed a Quick Race option, where you could drive what you wanted where you wanted. If you wanted to drive your favorite cars, you had to go to the Challenge Series, as The Run mode only had Tiers 4 and 5. And there were some great levels: Running from the cops in Las Vegas, fleeing for your life in Chicago, duelling on icy Independence Pass and dodging subway trains in New York. Trouble is, if you wanted to play your favorite levels, you had to go to The Run mode and play through an entire stage to get there.
Need For Speed: Most Wanted (2012): This game could've been great as a stand-alone game, or as a Burnout maybe. Trouble is, they branded it with the Most Wanted name, so you should expect expectations to be high. Yeah, so you've got good pursuits, lots of cars and an entire world, but there is little to no storyline. Plus, you can tell that Criterion made it, what with the drifting, takedowns and billboards. No offense to them, but with that name, it should've lived up to expectations. I can't even imagine the fan reactions if Criterion made an Underground 3.
So here I can hope Rivals can live up to the expectations. It looks good at first: police chases, the return of Ferrari and seamless (they mean it!) singleplayer-to-multiplayer transition. However, will it be as good as the previous games? I guess we will have to watch this space...