in other than a high magic environment, a Wizard wins, hands down
This still remains true, after all these years. In a high magic environment, magic items overwhelm the advantages of a Wizard - the higher the magic level, the more the effect.
Fighters (re: melee types) tend to suffer from the |immunity to X| problem, really. And all the M0bs doing damage, needing to be constantly healed. Granted, in an environment where healing is plentiful (meaning unlimited, really), then this problem is for melee characters less.
A Melee Mage (especially a MMM) of course makes use of melee, to smack their way through the m0bs to get to the Boss without depleting their spells, making rest a non-issue (which is why I created the MM in the first place - due to limited resting).
A MMM is much more flexible than any other character, being able to do just about everything (with the exception of the epic traps thing I mentioned) as long as they are not in a high magic environment. They can meet any challenge and best it (with the exception of AMZs). Countless years of experience in many different environments here - both off and online.
For the record, scroll use, potions use, and especially wand use has been incorporated into MMM play - depending on the environment, of course. I know of one variant that was an extensive wand user in an environment where there was lots of dispelling opponents, for example.
Scrolls, wands, and potions (to a lesser extent) have their uses, especially for buffing and for those spells that really do not do damage based on levels (unless one is playing in an evironment where the D&D PnP rules for scrolls, wands, and potions are being used, for example).
Still, even a watered down wand of x can be useful for preserving spells if so desired. I normally always have scrolls of damage soaking in my inventory, and of course scrolls with escape spells.
One never knows when one will need to retreat - which a Wizard is really good at when needed.
Multiclass Melee mages don't really work at low level. I know this because I play them. (and love playing them) but higher spell levels are always worth having, more so than Armour proficiency or damage reduction (at low level).
Further Sorcerer beats wizard in my experience at least. Flexibiltiy on the fly beats flexibility in preparation. And more of the good spells beats less but more varied spells. Skill points are neither here nor there.
Of course If you have a level 12 MMM build that can beat the druid with a dump level in cleric I'd love to see it. In fact I eagerly await your reply. 
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Actually, I already did a thread on this on the old forums, and many contributed to it. We basically did the break-downs for ALL levels, and did the comparisons mathmatically. MMMs won out in every level breakdown, EXCEPT in high magic level environments.
Basically, your "low level" MMM has a nice damage soaking, regenerating Familiar, with a level of Cleric, 1 level higher Summons (at the same time, of course) AND all the protection/stat-boosting/damage soaking/offensive spellpower that the Wizard enjoys, with little to no sacrifices. Proper assembly of your MMM is required, of course.
As for Sorcerer vs Wizard (MMM), well, we did this breakdown as well. The Sorcerer just suffers too much in flexibility, really (especially in environments where there are more spells available as just the "normal" palette). True, the Sorcerer is a plattform of mass destruction, but getting through the m0bs to get to the Boss, and preserving those spells is problematic, in the least. Creating a MMM based on Sorc is more difficult in my experience. Not saying it is impossible, nope, just saying that it is not as effective as using Wizard based on my experiences - YMMV.
To that, the Wizard has more skill points, and more feats - and is normally able to share spells, meaning that in a short time, the Wizard has just about all the spells available in that environment (dependingly, of course).
The Sorcerer does not enjoy these advantages.
Of course, after an environment is "known" - one can then tailor a Sorc to be more fitting (necessary spells learned to face the level of threat, etc). Still suffers from less skills and feats, however.
