Cavalary: Congratulations!
The series was my first purchase on GOG. M&M1 made me feel like slamming face first into a wall, didn't go further since, since at first I kept saying maybe I'll try that again, then that maybe I'll give 2 a chance before moving further, and only these days finally decided to give up on the thought for good and just look from 3 onwards, but no idea when or if I'll actually do that. So may just be left with 6 and the early part of 7, played around 2006-2007 or so.
GreasyDogMeat: Have to admit, I played the first one on NES. Found it to be superior in numerous ways. Of course that meant I couldn't import my characters but that was well worth the trade-off.
It may be superior in numerous ways, but it also suffers from what I'll call the Locust Plage bug.
Short version: If a Locust Plague gets a turn while in melee range, Game Over.
Long version: The Locust Plague enemy is unfair in the NES version. This enemy, which notably is fast enough to act before your party (at starting stats, at least), will deal 255 damage in the NES version. (In other versions, this enemy is a bit more reasonable; it can do 10 damage maximum per attack.) This is going to KO whoever the plague decides to attack, at which point, due to a bug, the enemies get an extra round of attacks. In this extra round, the Locust plague will, again, KO another of your characters; this cycle will repeat until your entire party is dead. Do you think this is fair? (I am suspecting an integer undeflow bug here.)
GreasyDogMeat: I remember wanting to play through the Might & Magic series.
5 years later and I've finally finished.
toxicTom: What are character import paths throughout the series? I mean, if you don't play on the NES ;-)
You can transfer from 1 to 2.
If 4 and 5 are installed on the same computer, they can be combined into a bigger game called World of Xeen. (Note that the GOG version comes with the games already installed.) You start in MM4, and by using pyramids, you can travel to and from MM5. (Note that spending a bit of time in MM5 might break the balance of MM4, so if you want MM4 to not be too easy combat-wise, I recommend not entering any of the pyramids until you have defeated Lord Xeen.
Edit: I believe that's all of the import paths.