Since I made a sweeping comment on monk's suckiness, I'll explain it. The most commonly cited reasons to play a monk are mobility and defense against magic.
1. Mobility is just plain bunk once the Fly spell comes into the campaign. Fly is just as quick as all but the highest level of Monk, and the Monk stands no chance against a flying opponent with ranged attacks. It's not hard to get a hold of a magic item which grants flight as well.
2. They do in fact have good defense against magic... but defense doesn't win the game by itself and the combat system favors the attacker over the defender. A monk has good SR, once he gets it, but with the availability of spell penetration and various other tricks, a spellcaster will eventually harass the monk to death.
3. I say that the monk's strengths can be duplicated by magic items, but the monk can't do the opposite? True. A monk can't use magic weapons, magic armor, can't add SR, and a few other things. Their natural abilities already have all of that. If you really want to use all of that junk anyways, you're playing a neutered fighter. So why not play a fighter/barb/ranger and take advantage of better HD, BAB, and weapon selection.
4. Monks are severely hampered by multiple attribute dependency. They are melee fighters, so they need strength. Their AC is based solely on their Dex and Wis, so these should be high; a few of the monk's specials also rely on Wis. They have low HP, so they need a decent Con to be on the front line. They also want that Con for a good Fort save. Cha and Int can be dumps, but Monks have good skills, so Int is useful. This means the the character that you need to sacrifice some of the strengths because they rely on different things.
5. I almost forgot this. Paladins whose primary or secondary stat is Charisma have better saves than monks. They also get the good weapons and armor that monks can't use, in addition to some cool divine abilities and spells.
6. Monastic life is by definition, secluded. When creating a character concept, most Monks need extenuating circumstances to go adventuring. It's difficult to integrate a Monk into the group in-character
There are a few good points: Monks have a very high touch AC; hard to hit them with incorporeal attacks and with rays. The incorporeal thing is a two-way street though, since they also can't hit incorporeal easily. Flurry of Blows (statistically superior in 99% of situations to normal attack) gives you the full strength mod to your vitrual off hand.
I think that sums up my objections to the monk.
-nameless