[Aerich]

Deep gnome monks. Some people think monks suck, but the real value of a monk is in its ability to draw the attacks of huge numbers of enemies and take relatively little damage (if appropriately buffed, of course). The trickle-down effect on the rest of the party is significant, in the sense that much less healing and/or summoning spells are required. It's also nice to throw AoE around the front line without worrying about friendly fire.

A deep gnome monk is, IMO, the best meatshield in the game for normal mode after it gets to about lvl 5. It becomes all-but-impervious to magic at lvl 13 (race spell resistance stacks with class spell resistance), and by that time it has enough HP that the rare hits that do get through aren't that much of a problem... when using Stoneskin, of course. I haven't taken one all the way through HoF mode yet, but it should be fine once it hits lvl 20 (Perfect Self - damage resistance of 20/+1). Note that monks are most effective against hordes of low-medium level enemies, archers, and spellcasters. They will have trouble against very heavy hitters. That goes for normal mode as well as HoF.

The dreadmaster/monk combo is interesting, but if using a deep gnome it results in an XP penalty. Perhaps a better combo for a deep gnome is an illusionist/monk, but I would only suggest that for a HoF game. The extra caster-only spell buffs aren't really necessary in a normal game beyond the ones a deep gnome already has, and taking illusionist levels (recommended 5 or 6 before starting in with monk levels, as you can't go back and forth) will significantly delay higher monk levels, resulting in a lesser ability to tank in the mid-game of normal (less HP and level-dependent monk benefits) and in the early-mid part of HoF (really slows down access to lvl 20 monk feature Perfect Self).

The only major problem with the monk/illusionist combo is stat point distribution, since you cannot nerf Int as most min-maxers would with a pure-class monk. Con and Str should take the hit, because you need Dex and Wis for AC.