For my money, Planescape is my favorite of the Black Isle era stuff. Of the non-Black Isle stuff, Ravenloft and Dark Sun.

Yeah, i guess two decades is still too new... *eyeroll*

You should play Baldur's Gate in the NWN2 engine. It's a blast!!

Personally I'd never consider 2016 games old school. It has to be 2015 or earlier. WT3 and the like...

Did they actually finish that? I'll have to check that out.

Ew! But that is like so old now. Totally outdated. I can't play anything that's older than like a day, man.

Especially if you play on a laptop, one technical reason to choose the Enhanced editions might be this:

https://www.gog.com/forum/baldurs_gate_series/baldurs_gate_12_enhanced_editions_also_100_or_50_cpu_usage/page1

Meaning, for some reason the original versions of Infinity engine RPGs try to maximize your CPU usage, even up to 100% if possible. Some kind of error in the game engine design. However, nowadays this is not maybe as bad as it might sound, because:

1. With modern CPUs, these games can't rob full 100% CPU usage anymore, thanks to HyperThreading apparently (so it may be constant 50% CPU usage instead in one CPU core). This was more problematic with older 1-core CPUs which would run at constant 100% all the time with those games. That's how I noticed it, getting overheating problems in one old laptop where I was playing the original Baldur's Gate.

2. Even if you feel it is a problem, at least with laptops you can limit the overall CPU usage. In the aforementioned laptop, I could choose to use some "Save Power" power plan that restricted CPU usage to "low". The game would still run the same, but would use less CPU power (and electricity), and the laptop would run cooler too. I just had to keep switching that power plan on and off when playing (or not playing) Baldur's Gate or Icewind Dale.

The enhanced editions have fixed this issue, and those games use much less CPU power, also dividing it to different CPU cores. They also use less power/electricity.

Not quite sure if there are other reasons too, like the original Baldur's Gate and icewind Dale have quite poor quest log systems (hard to keep track which quests you've completed and which are incomplete); IIRC the journal system was improved in the Enhanced Editions. Baldur's Gate 2 original already has a quite good quest log system, if I recall correctly, this was mainly the issue with the early Infinity engine RPGs.

Not gong to get into a debate on the two versions, you can find plenty of information on that elsewhere. What I will say is that if you play Baldurs Gate, consider looking at Big World project:
http://www.shsforums.net/topic/44661-big-world-project-bwp-v90/

It adds (depending on the option chosen - I tend to go with tactical) a shed load of extra content.

Oh, and he prepared to lose a few months playing them, it is a massive game. I have been through several times, a couple of times solo character!

Iwd 1/2 are more about faster combat and so are shorter and less story based. Planescape is almost all about story and atmosphere.

Frankly, I don't think it makes much of a difference, since after all the "Enhanced Editions" of the Infinity Engine games have very little changed from the original.
It boils down to innate widescreen support, the ability to zoom, and some extra content that's pretty poor quality (that's actually the main reason I hate Beamdog, to me releasing a barely changed version of a very old game for twice the price it used to be is basically a scam).

In discussions you'll see often mentioned that all the Enhanced Editions of the Infinity Engine games (BG, BG2, IWD, PST) have to offer is widescreen support, that can also be done by mods, but this is false information.

One of the most useful improvements over the original games is the portrait icons showing what the next action is a character will be performing. When you order an action to a character, such as casting a certain spell, the character will not perform that action instantly as the time in combat is divided into rounds and that rounds into segments (indicated by the speed factor) and wether a new round for that character has already started and the speed factor of a weapon or casting time of a spell (0=instantly at the start of the round, 10=a full round) determines when the action will be taken.

So time will be spent waiting for the character to cast a spell. When an action is taken, it's shown in the combat log, but this can scroll by quit quickly in a big fight. With the old game, I found myself repeatedly giving orders if I didn't know if I had already given the order or if it was already done, but with the Enhanced Edition, you can see at a glance what the next action is that will be taken by the character in question.

Another useful thing especially if you're new to the game, is then new character screen that breaks down the stats for to hit chance and armour (now as Thac0 - to hit armour class zero - and AC - armour class) respectively. The weapon itself, bonuses, a character's STRegth and DEXterity all influence this. In the character screen of the Enhanced Edition, you can see how all these factors for the equipped weapons and armour influence the stats.

Non of these can be found modded into the classic versions. The Enhanced Edition made it far easier to mod the originals as well, giving modders far more freedom to things that formerly where 'hard-coded' and couldn't be changed.

*edit: a third very useful feature is with the Enhanced Edition you can switch between wielding a weapon used with two hands (a two-handed melee weapon or a bow) and wielding a shield + one-handed weapon without the need to go into the inventory and de-equip all two-handed weapons in your quickslots before equiping a shield and vice versa. In classes Baldur's Gate 1 this last feature was especially annoying as the game un-paused when going to the inventory, but even with classic Baldur's Gate 2 this was a nuisance.

For me, the main reason I played with the EEs was the display / interface. I could never get the widescreen modded classics to look good on my 13" 1080P laptop. At 1920x1080, the interface is way too small. At any other resolution, everything is blurry from using a non-native resolution.

The EEs solve this. And now that I've played nothing but the EEs for a few years, I can't go back to the classics because of all the little improvements that DubConqueror mentioned.

I still play the mentioned games the "classic" way. I tried the enhanced versions myself but went back to the originals. There are some reasons why I stay with the original games: The enhanced versions don't look the same anymore with their changed gui (I loved the original gui of BG1). I don't have any use for the biggest "feature" of these enhanced versions: higher resolutions - these games were intended to run under 640x480 (or 800x600 in the case of BG2) and all the carefully crafted maps depend on this resolution to give you just the right view of the gameworld and the proper feeling of exploration. I also don't like what Beamdog did to the games by adding their stuff, it just doesn't fit at all. I don't know how the modding situation looks with these enhanced versions, but there are some mods I play with in the original games. Overall I don't like the enhanced versions at all and see not a single reason why I should play them.

edit: Oh yes, I forgot to mention the terribly ugly movies in the enhanced version of Baldur's Gate. While the original movies are certainly not of the best quality for today's eyes, they are at least decently rendered, fitting for the game and give some flair of adventure. The enhanced version "features" only these abysmal "comic"-movies. It's a disgrace.

They're some ways through BG2 at the moment. BG 1 is complete and playable to the end.
I prefer TUTU, but damn, you can't go wrong with either.

Yeah, but I love the original games. I don't want to add all those changes. The reason I play them is because they were already awesome.