Hello everyone!

Is it easy to learn and is it fun?

As easy as any other D&D game that isn't basic/classic. Those are easier.

I prefer the 1st and 2nd editions as a whole (especially since the 1st is paradoxically so well supported these days by open projects like OSRIC and several adventures are still being published by the likes of DCC) but if you want something modern, stick to ed. 3.5 (d20). I'd stay the hell away from 4th and I didn't really enjoy 5th either.

Same here, but getting more into OD&D (original edition pre-1e) more.

I usually run and/or play Pathfinder myself and if I find something from one of the earlier editions (whether it be anything from the '74 white box + supplements to the latest OSR releases) I just port it the best I can to Pathfinder. I don't really have any 1st hand knowledge of 4th and only briefly read some 5th edition material.

That is interesting, I feel the same about the good old editions. AD&D or Second Edition was a superb system, you could play it as an encounter-based combat game (Baldurs Gate) with light roleplaying or as a fully-fledged deep roleplaying character-based making-stories up game were the numbers served as guidelines.
3rd Edition was very system-based, very well suited for character optimization and video games, the whole notion of character builds started there. Problem is, it detracted from the roleplaying aspect in my opinion with all these classes, feats, talents, prestige and the whatnot. Did not touch 4th edition since the ruined the Forgotten Realms :-)

HOWEVER, I am absolutely digging the fifth edition. It is almost like in the good old days, just with much more elegant better mechanics (THAC0, I am looking at you).
It is very elegant, it is extremely flexible and it refocuses on what made the AD&D great. It is less number-crunching and character-build based and instead gives the dungeon master the freedom to adapt the system to whatever he or she needs instead of having to limit players to a managable level like in 3rd.

If you require more strict rules to keep the game going or prevent arguments, you will need to decide on these beforehand. The Dungeon Masters Book gives you many good examples of how to do things instead of dogmatically declaring how to do things. In short, 5th edition gave me back D&D. To quote GameStop: "Power to the players".

To answer the main thread question, it is somewhat easy to learn for a pen & paper RPG. Definitely easier than 3rd or 2nd edition. If you have a good DM that is, it always depends on the DM. All you really need to get going is the Player's Handbook which contains everything a player and a sufficiently creative DM needs to play.

Note that the beginner's box is a really lousy start, focusing very much on difficult combat encounters. A good DM with a creative initial adventure is much better.

2nd E and 3.5 tie for my favourite but since they are out of print the books and supplemental materials cost an arm and a leg. Looks like I'll be picking up 5e. Thanks for the advice!

You can always buy digital.

Drivethrurpg has Original, 1E, 2E, 3.5, multiple versions of Basic/classic.

If you are familiar with 3.5, I suggest Pathfinder. You can easily use the D&D lore if you got the manuals/already know it, and the rules are quite similar, with minor tweaks (improvements IMO).
The core book is relatively cheap and you got all the rules available legally online for free (without pictures, but you don't need to throw another 20-40 bucks to get classes as ninja, for example).

I currently play Pathfinder, and the only problem I find is the lack oh Beholders. And if my DM wanted, we could still convert them from 3.5, since they are compatible. I am personally enjoying it a lot.

I prefer to buy from drivethrurpg these days, saves space, can have eveything on my pc or tablet, no DRM, etc.

I'm a huge fan of Spoony but I sometimes don't agree with his points.

Wasn't that one his most criticized reviews, because he didn't actually play that D&D version very much?

No they don't. http://www.dmsguild.com/

As do I (Man of Steel being the prime example). But even more often I do agree with him, or at least think he brings up some good points. In this review he might come off as a little too hostile towards players who just like to play a different way, but he still makes some good points. The advantage/disadvantage system for example really sounds like one of the worst ideas I've seen in any RPG.

Maybe. I think he even admits in this video that didn;t play it at all, it's just his opinion after reading the manual. Still, especially when it comes to RPGs I really respect his word, his videos got me back into roleplaying after a long break, and pretty much everything he talked about in his various videos I found to be true, or already knew to be true from my own previous experience.