I made a thread asking for recommended 3rd party material. Now I want to know if there's any recommended D&D books made by Wizards of the Coast.
Frostburn, Sandstorm, and Stormwrack:: Are these books any good? Even if a didn't plan on campaigns set in these locales, do they still contain useful material?
Dungeonscape, Cityscape: I heard good things about Dungeonscape, especially the Factotum class. Rich Burlew also worked on it, if I recall.
Monster Manual 4: The only Manual I don't own. Heard a lot of mixed reviews about it.
In return, here are some recommendations of my own!
Tome of Battle: WotC's best attempt at closing the power disparity between casters and noncasters. A lot of guys loved it for this, but many hated its "magic-like Wuxia" and pseudo-spell system. I fall into the former category.
Spell Compendium: A treasure trove of awesome spells, some new and some taken from a variety of earlier sourcebooks. A must-have for any spellcaster.
Magic Item Compendium: This revolutionized my games. I really like its emphasis on cost-efficient, reusable magic items.
Red Hand of Doom: An all-around cool adventure. It keeps to the classic "defend civilization from the horde" scenario with dungeon crawls and wilderness exploration, but puts an interesting spin on things with a time limit and opportunities to help in settlement defense.
Player's Handbook 2: This is a rare treat, a book notable for its large amount of player-friendly classes and feats of good quality (Beguiler and Robilar's Gambit, anyone?).
Libris Mortis, Lords of Madness, Fiendish Codex I & II: Books themed after certain monster types. A great mix of fluff and crunch, provides a nigh-endless amount of adventure ideas in each one!