Yeah, It'd be core 5e for me as well.

I embraced 3.0 when it came out but stuck with it too long. I ended up hating the supplement mill, endless prestige classes, feats etc. I will say that the OGL gave rise to some good stuff.

4e was a joke for me. Just wasn't D&D.

But I liked 5 when it came out. But WotC had to wokify a good thing. Ah well. I'm glad I have the OSR.

Long-lived races is one of those things that often doesn't hold up very well when you look at it closely.  Not that's it is necessary to do so.  You can just say that starting elves are 80+ or whatever, and leave what happens to the adolescents as unmentioned most of the time.  For a fun take, I've always thought that's where half elves come from--"teenage" elves trapped with their hormones for the better part of 30-50 years. 

If I'm going to use the defaults and need an explanation, I usually go with the cultural one.  Maybe elves in particular aren't fully mature until 30-40 or so, the same way many humans are still growing in some minor way between 20-25.  We don't usually think of a 20 year-old human as not physically mature even though most of them are not "done" yet.  If you think about it, it's not uncommon for a human child to reach full height (though not bone and muscular development) before 14, or just over halfway to their full development.  Elves still gaining height up to age 25, and most of that before age 20, isn't a great leap.  There have been times and places where the local human culture considered those in the 25-35 range not fully adult yet.  Heck, even in the USA, where it's all "they are kids" when questions of responsibility come up but "they are adults at puberty" when questions of letting them do whatever the hell they want come up, the insurance companies are still giving higher rates for driving up until age 26 and/or marriage.  So I'd think even in a youth-oriented elven culture, it wouldn't be odd to think of 50-100 year old elves as mostly adult for most purposes but still not fully there.

Now, what I usually do is chuck most of the extremes out the window by saying that most dwarves lives to about 150 and most elves live until about 250.  Their old age can be productive, and occasionally one lives until about 250 or 500, respectively.  Or alternately, elves are immortal but aren't player races.  I don't usually enjoy having effectively immortal races as player races, because it  monkeys with all kinds of timeline mysteries.  It's very hard to justify digging up ancient information from 2 centuries ago when two of the PCs were alive then.  Not impossible, just hard.  But I like to do that a lot, and this screen monkey is tired of jumping through that particular hoop.

Core 3 plus Xanathar's will get you set pretty well.

Tasha's is very optional.  A few of the additional subclasses are decent, but not enough on their own to justify the price.  The new optional rule on attributes was stupid.  Most of the subclasses are weird and don't have a true D&D feel. 

Would consider:
Rime of the Frost Maiden (Played it and enjoyed)
Tales from the Yawning Portal (Collection of older good adventures converted to 5e)
Candlekeep Mysteries. A collection of short adventures for various levels. Okay if you need that.
Original printing of Volo's Guide. Some lore, some monstrous PC races.

On the fence about:
Storm King's Thunder (Read, but didn't play. They try to have level 1 characters start a campaign to fight giants, and band-aid it by giving you powerful NPC help. Not every adventure book has to start at Level One. )


Own them and would say not worth the price:
Theros.  Definitely not worth the price. Less than a 3rd of the book is useful. Better off finding a 3rd party Ancient Greece setting for half the price.
Sword Coast Adventurer's Guide.  My 1st disappointment with these being not worth the price.  A few good subclasses in a very thin book.  They have crates of Forgotten Realms material in the back room and they could barely come up with 156 pages?
Wild Beyond the Witchlight. Underwhelming.




Not interested:
Ebbaron, Ravnica. The best settings books are 3rd party, and I'm not into second-hand MtG ported stuff. (No offense to MtG players, but it's just not my gig.)

And outside of the core 3 books, which others would be considered "must have"?

While nothing beyond the core 3 is truly must have, Xanathar's has the following major stuff omitted from the DMG/MM:

1. Proper encounter tables, using only MM monsters. This was a noticeable omission from DMG/MM.
2. Decent magic item crafting rules, with much better durations & pricing.
3. Other good downtime rules - though some in the DMG remain good.
4. Common magic items - more fun than necessary, but good for a common-weak-magic sort of setting.
The lists of names are handy but not vital.

And it has some good stuff for players, like the Forge Domain cleric and racial feats, though nothing really vital.

I certainly reference XGTE in play a lot more than the DMG, though the DMG does have good discursive material. It suffers from a really weird, non-intuitive structure, with some of the most advanced material right up front.

I'm sure the posters at EN World think their voting is 'stunning and brave'.

Just like your criticism.