On Moon Druids:
Moon Druids are excellent, excellent team players with great spells, melee capability, and no stat dependency at all.
On AC: I've seen a lot of discussion on this thread about Barkskin, a 2nd level spell which lasts for one hour with concentration and gives you AC 16+. I've seen no discussion about Mage Armor, a 1st level spell which lasts for eight hours and gives you an AC generally between 14 and 18. (CR 1 Giant Hyena gets AC 15, and so does the excellent CR 2 Giant Anaconda^H^H^H^H^H^H^H^H^H^H Constrictor Snake. Air Elemental at level 10 gets AC 18.) Mage Armor generally stretches your temp HP by an extra 25% or so, which could be like having an extra 50 HP over the course of a day. Very worthwhile for a 1st level spell. If only you were acquainted with a wizard who knew that spell...
Hilariously awesome partnership: a Mobile Sentinel Moon Druid rhinoceros being ridden by a Mounted Combatant Paladin/Warlock. If the enemy closes to melee range, paladin hits them with Booming Blade (probably at advantage), then the rhino hits them again and rides away (because Booming Blade). If they don't close, paladin blasts them with Eldritch Blast, and then the rhino charges them for extra damage (4d8+5 total), or just lets the paladin kill them with impunity. If the enemy ever manages to close to melee range and attack, they have to attack the paladin's AC, and the Moon Druid hits them (because Sentinel) with a reaction attack because of it.
On spells: there are two kinds of Moon Druids in theory, those with crummy stats and those with good stats. In practice I've only ever seen Moon Druids with crummy stats, because good stats turn into other classes, but if you for some reason were playing a Moon Druid with decent Wisdom (16ish), you might be tempted to cast Entangle before you shift to bear/wolf/snake/etc. form. Having a restrained enemy who needs to waste his actions trying to break free will boost your party damage output and simultaneously stretch your beast HP further. It costs you one round of attacks, but you can still move into position to tank with opportunity attacks. If you don't have decent Wisdom, you're likely to stick to non-stat-dependent spells, of which the Moon Druid has lots of awesome ones: Pass Without Trace, Spike Growth, Conjure Animals are all stand-outs. Polymorph can be pretty good too, depending.
There are those who say the Moon Druid is great for level 2 and then fades. That's not my experience. A Mobile Moon Druid stays relevant all game long (even if his stat array is only 10, 11, 10, 13, 9, 8), and he experiences major jumps in power on a regular basis. Conjure Elemental, Conjure Animals V, Planar Binding, Anti-life Shell, Transport Via Plants, Reverse Gravity, Regenerate, Animale Shapes, Antipathy/Sympathy, Shapechange, Foresight... these are all great spells, and unlike a wizard who has to choose only 4 spells per spell level, a druid knows them all automatically.
On feats: I always want Resilient (Con) and Mobile eventually, and sometimes Lucky. Other than that I don't care (and haven't played a Moon Druid to high enough levels to get the full six feats anyway) but would probably just boost Wisdom by +6 (probably Wisdom 18-20). Mobile is fantastic for an Earth Elemental with Earth Glide. Also, if you read the text of Mobile closely, it works with melee spell attacks as well, of which Contagion is one... so theoretically at 20th level (when you get Archdruid componentless casting) you can strafe the enemy from the air (Air Elemental or Giant Eagle/etc.) or beneath their feet (Earth Elemental), afflicting them with diseases on each round until finally they succumb to Slimy Doom or Flesh Rot, without them ever being able to retaliate. Even before 20th level you could do this in druid form, I just think doing it from below the ground Tremors-style is cooler.
Also, Sentinel can grant a Moon Druid a use for his reaction even in beast form--it's good for action economy.