5e is great for balanced play. 4e is great for brand new roleplayers and people who don't care about gameplay. 3.5e is great for absurd, superhuman play that gets up to near-Exalted level shenanigans, exploiting little tricks and features from a dozen+ splatbooks to create the perfect machine for... whatever you want to do, really.
So, in brief, 5e did a lot to solve the problems of prior editions without fucking up too much in the process. It doesn't have perfect asymmetrical balance, but it's better than 3.xe, and it's not the boring dross that was 4e. If you're just getting into DnD, 5e is an excellent place to start -- all you need is the PHB and someone with a copy of the DMG, and players can technically get away with using the freely available Basic rulebook. It's set up so that just about anything can be decently viable without relentless optimizing.
By the same token, nothing in 5e can be broken to the same exceptional degree that a lot of 3.xe could; the Concentration mechanic prevents the old 3.xe style of massively layering buffs, debuffs, and CC on top of a more flexible casting system with reduced "depth" of power. In short, martial, skillful, and secondary caster classes have had their kits generally made more coherent, while primary casters have been reined in, made simultaneously less overwhelming and more reliable on the low level with things like at-will cantrips and ritual casting.
tl;dr: 5e is good.