I have acquired a 2002 LeSabre Limited that has 161K miles on it. I am replacing the water pump, and will also put in new plugs, and wondered if it is worth it to pay for the double platinum or even Iridium plugs, or just go for the cheaper copper or platinum. I don't expect the car will go another 100K miles, but I have heard in the past a lot of comments about how some plugs are great and some are no good, so I'm just asking for any advice on what to put in my car.

I'd pay extra. If you don't beat it much and it'* not beat too badly already then it probably has a good 80,000 left in it. Be sure to service the transmission.

I have a friend that had a '98 LeSabre that started showing the CEL for random misfire 10,000 miles after she bought it (odometer showed 125,000someodd at this point). I chased it for a bit then pulled a plug. Autolite $2.00 plug, new looking.

Replaced with Delco Iridiums and voila' no more light after a few drive cycles.

AC Delco Iridium'* are all I'll use in my 3800 II and 3800 III.
If you shop RockAuto you can get a 2.00 rebate in the mail per plug.
So in the end 3.31 a plug, not bad IMO, I just got 6 of them myself, still waiting on the rebate to come in though.

ACDELCO 41101 Professional; Iridium

RockAuto Current Promotions and Manufacturer Rebates

OEM......

Copper (NGK) or irridium. Don't use platinum. They don't work very well for very long in our ignition configuration.

That'* not even counting that they like to explode in the supercharged application.

Thanks a lot for the really fast responses. I am ordering a water pump, radiator, thermostat and Delco Iridium plugs from RockAuto for about $131, including a 5% discount I used, plus I will get back $12 for the plug rebate for a total of $119!
I love these car forums; you guys are great!

Very welcome, RockAuto has some great deals, always compare with Amazon.com prices though, sometimes Amazon has stuff a tad cheaper, but in your case RockAuto was the way to go, you got all of that for a decent price, nicely done!
I'd expect it to take a few weeks for the rebate, but you will eventually get it.
You will have to cut the upc code from each individual spark plug box, and mail them in.