After watching four seasons of mixed martial artists who live in one house, scarf down pasta, and trash-talk before entering the ''Octagon'' fighting ring to box, kick, wrestle, and generally pummel each other, I've got to say this fifth edition may be the best. If you're not watching Spike TV's Ultimate Fighter 5, now a little more than halfway through its hammer-fisted season, you are missing one of the most exciting, goofy, addictive reality shows on the air. It's not too late to get on board. This season is the first time for the lightweight division (155 pounds and under), and these strutting bantam roosters are just more nutty and ornery than any bunch that's preceded them they seem to have more to prove.
Eloquence is not their most developed skill. After one knucklehead wrote an insult on a wall of the shared house, another indignant knucklehead spluttered, ''I take it offensive toward me!'' Even the coaches mixed-martial-arts pros B.J. Penn and Jens Pulver hate each other; in fact, during the June 23 live season finale, they will climb into the Octagon themselves, to try to choke out or generally damage one another.
What makes ''ultimate fighting'' such a hoot anarchy-with-rules competitions that permit all sorts of down-and-dirty techniques transfers beautifully to the decadent, mind-numbing elimination conventions of reality TV. One of the more irony-appreciating fighters said cheerfully after an outside-the-ring squabble, ''It's a sad day for humans.'' But a great one for fan-viewers. B+