To the OP:
Don't try for some super-strong +LA character. They tend to end up as paper tigers. Like you mentioned in the first post, you want someone who can stay alive as well as kill stuff.
Basically, the most efficient way to achieve major ass-kicking in a hack-and-slash campaign is magic. Especially if you have the option to attack and retreat. (Buff, fight/blast, run away. Repeat as needed.) ) And for melee, shapechanging magic is king. At level 10, you usually want to be a cave troll (MM3). (Possibly unless you can use outsider forms.)
Wizards and sorcerers and can change form with polymorph or draconic polymorph(5th, Draconomicon). If the DM lets you use Skip Williams' item rules for wild shape, the master of Many Forms (CAdv) is pretty good. Even a cleric can get polymorph, with the Transformation domain in Races of Eberron. Psions have metamorphosis.
Feats like Carmendine Monk (Champions of Valor, for a monk/wizard) or Ascetic mage (CAdv, for a Monk/Sorcerer) lets you add you main casting stat to AC when unarmored. Another trick for a melee sorcerer is to get a level of Sacred Exorcist (CD) and get the Divine Might (CW) feat.
If you like the idea of a shapechanging melee char I could post a more complete character. (Depending on what you prefer - wizard, sorcerer, cleric, psion...?)