Well all four will be able to do the quest if you really want to get it done, I'm pretty confident. So you're still back to having to pick the class based on the class
[You must be logged in to view images. Log in or Register.]
They're all great. Your order is the same I'd consider them personally.
Magicians are neat, but their extreme focus and gimmicky utility (mod rods, COTH, summoned items) don't appeal to me when we're talking about playing the character for hundreds of hours and more, even though their variety of pets coupled with malo line and nukes and utility make them a solid all around class.
Wizards can be a lot of fun. Ports are great (and translocates are better!), they have nice CC via stuns and awesome roots, quadding and AE groups are cool in their own ways, they're top notch DPS in raids besides being important to get everyone together with ports. There IS a bit of an art/science to nuking properly without pulling aggro or leaving some of your potential unused and they get big boosts from their current levels overall in Velious, imo.
Necros have a huge arsenal of spells. Invis, IVU, feign, harmshield (two of them!), a pet, snares, roots, mez, fear, lifetaps... those give you great ability to move through a lot of places and to accomplish difficult pulls whether solo, grouped, or raiding. Necro heals are phenomenal when used correctly in groups, twitch is a very valuable utility. Necros can also summon corpses, rez, nuke (multiple resist types), dot (4 resist types!), charm, summon pets, evac, regen mana like crazy, sacrifice the souls of other players for fun and profit, and more.
Enchanters are simultaneously more specialized than necros while being more versatile. You'd think they're squishier targets because they don't have feign, harmshield, or lifetaps, but rune+bedlam are pretty damn awesome and quick stuns+mezzes+roots give them toughness in an indirect way. They're almost totally reliant on charm to solo, are expected to be charming in most group situations or else aren't considered to be pulling their weight... but charm IS incredibly power. Chanters can move through dungeons more quickly than necros but with more risk because of better lull spells but no feign/harmshield. Haste, slow, tash, c2, and CC make enchanters amazing in groups even if they don't charm. Then they still have illusions, faction spells, cool but not-frequently-used debuffs (enchanters can debuff strength by like 200 points, lol), mem blur, mana taps, the best dispels in the game by miles, and more.