Let's throw a couple cents here.
3E is no less crunchy than 2E, nor is it really 'simpler', what it is, is more streamlined.
Some of it is getting rid of d20 roots (ie: the grappling mechanics, the carry weight mechanics, sneak attack, switching from having a stat and a modifier to having the stat be the modifier, the changed time/value/whatever table) and switching to something less troublesome to work with.
Some of it is consolidating skills.
Some of it is a step further from what Ultimate Power did for 2E, ie: instead of having 'strike' and 'blast', you have 'damage', and just get the range extra if you want it ranged. Instead of snare, dazzle, and all those other status effect powers each with their own slightly different mechanic, you have Affliction, which lets you custom-build one.
There's also the change to the damage mechanics, instead of tracking lethal and nonlethal separately, it's just all in one, with powers like healing and regen being simplified.
Some of it is rebalances, like the changes to impervious, changing save or dies for graded results (failing is generally not too bad, but failing for 5 or more tends to suck a lot)
Now, I'm not 100% happy with all the changes, tho to be fair for most of them, I wasn't happy with the 2e alternative either. An example is impervious: it was waaay too good, but now it is mostly worthless.
Splatbooks:
Book-wise, you only need the hero's handbook. The others are 'nice' as advice, as stuff to plug into your game to speed up your campaign creation or just to get your creative juices flowing, but by no means necessary.
Beyond the main book, most of the 2e's books were fluff and advice on how to run campaigns with X flavor, a lot of characters you could just import and refluff into your game, and sometimes with some clever ideas of how to build things with the existing tools. The fluff is 100% usable with 3E, the character examples are buildable, if not likely to fall within the same PP. The clever uses is a mixed bag, some you can use, some are already implemented, some are no longer valid or even useful.
The exceptions to this were the GM manual and Ultimate Power, the former had a whole lot of alternate rules, and the later did some serious work on the powers. 3E's GM manual has some alternate rules and stuff, but a whole lot less, and it doesn't need Ultimate Power because the manual already went full tilt on that direction.
Since it did go full tilt in that direction, it's a little harder at first to translate your fluff idea into a mechanical power when it diverts from the basics. This is where Power Profiles comes in, lots of premade powers, suggestions and thematic advice, categorized by power themes (animal, cold, fire, armor...).
The 3E version of Gadget Guides deserves a honorable mention. Much, much better than it's 2E counterpart, it's organized like the Power Profiles book, it also has slightly tweaked rules for inventing, and some seriously sweet work on expanding the rituals ruleset to allow for more concepts. Can you say Wuxia meditation magic?
Thread Reports, and it's DC counterpart, Heroes and Villains, are just character profile after character profile. Useful, but not necessary.
All the Emerald City stuff is just more on the Freedom City setting, just in a neighboring city.
Neither Cosmic Handbook nor Supernatural Handbook have 2e counterparts. Both are like the bulk of the 2e books like <whatever> Age, Mecha & Manga or Hero High: lots of fluff, advice on how to set the tone, little optional adjustments to the rules or extra ones, and a bunch of pre-made examples of things. Cosmic treats with everything space, Supernatural, oddly enough, is not a Book of Magic counterpart, it's not regular comic book style magic. Instead, it's horror and mystery, stuff in the style of Lovecraft, Silent Hill, the old-style horror movies or maybe Constantine.
Other than those two, there's revised versions of Hero High and Wild Cards, and there's DC Universe, which is basically Worlds of Freedom but for DC. Haven't checked out Watchguards.
Teh SRD
Lastly, and this is quite the reason to switch to 3e, is that there's an official and free SRD:
http://www.d20herosrd.com/
It has most of the Hero's Handbook sans some setting-specific fluff and some stuff renamed (hero points renamed victory points), it even has a few chapters from Gadget Guides. More than enough for most players, which seriously widens your available candidates for games.
This message was last edited by the user at 19:57, Tue 12 Dec 2017.