Is it necessary to clean every record?

I'm constantly buying used records, some of which are in excellent to mint condition. I put them in an ever growing stack of "to be cleaned" records, some of which are now several years old, because I have a rule not to play records that haven't been through the VPI machine. Is it really necessary to clean the ones that appear as if they've never been played? I listen to a Planar 25, Classe integrated, and Spica TC-60's. I'd appreciate your thoughts.
It's up to you. The least that could happen is that you will get some crud on the stylus (just clean it off) and the worst is that their will be "hard" particles in/on the LP that will damage it, however slightly, when played.

New and seemingly unplayed LP's are usually very noisy when played without a cleaning from my experience (there is some kind of white/light powder in the grooves and on the surface).

Maybe try a good "hand held" wet brush and a dry carbon fiber brush if you don't feel like using the machine (this is easy to do while the LP is spinning on the table)? I do this often when I get home and want to listen to a new purchase that looks fairly clean (no boogers and such:-). I zap it with a Zero/Stat, run the dry brush, run the wet brush and end again with a clean dry brush (30 seconds tops).
Why have a VPI if you're not going to clean each new disc. I spend 2-3 minutes per disc for a thorough wash and rinse with that machine.
Yes, it is.
Only if you're obsessive compulsive. I clean records that appear or sound dirty. It doesn't always help, but at least I give it a try. With brand new records, I don't usually clean them before listening(I know, burn me at the stake). If I don't like them, I'm not going to keep them and it seems a waste to spend time cleaning them until I'm sure. By the way, I use a Nitty Gritty 1.5FI and it takes me a minute and a half max to clean both sides of an LP.
Not only every record but everytime it's played. At least in my experience this gives the best long term results. any dirt, even surface dirt, can be ground in by the needle. If the record is cleaned befor play this reduces the possibility of this. To me, it's less of a sonic benefit than a long term, record lasting benefit (as records are expensive and sometimes difficult to replace). Some people use a carbon fiber brush for the "in between" deep cleanings. This dry method gets rid of most of the loose dirt, but I still prefer using the machine to clean each time--I guess it is obsessive compulsive at that point.
What I do with used records is to clean them with my Nitty Gritty, then treat them with Gruv Glide and place them in a new poly lined sleeve. I wipe the jacket with a slightly dampened cloth and, after drying, store in a "japanese" resealable cover. I put a "GG" on the cover with a magic marker. This way I know an album is clean and the need to reclean is minimized by using a new sleeve and cover. The cover also protects the jacket from deterioration. I usually do the same with new vinyl.
Yes you have to clean your records.It is a must its like driving a clean car vs. a dirty car the clean one always rides better and the music sounds better.
That is part and parcel of the great world of vinyl. Why forego such a treat. Even the dirt that you don't see can affect the record. Firstly, it may not sound right, secondly, you can damage the record permanently by having the stylus go trough miles of crud. You have the machine so why not use it. Call it work. Call it a ritual. Just do it. Have cds spoiled you or what?
It is only necessary if you would like to maintain optimum performance and reproduction with minimal wear and tear on the vinyl and stylus for more than one play. Sean

PS... Repeat this mantra :

Clean the record, play the record. Clean the record, play the record. Clean the record, play the record......
Dear Easy E,
Sean is absolutely correct, "as usual". Clean & Play. I might add that jphilips method of nitty gritty followed by Gruv Glide has worked extremely well.

I belong to an informal group of music/hifi buffs, between us we have 25,000 records. We all use a VPI or Nitty Gritty followed by a treatment of Gruv Glide. The improvement in sound quality is noticeable.
I am a lazy one. I mostly have new records or they are in excellent condition.
But I agree with all above. I clean now more and more my records with my VPI, even brand new ones. There is definetly a difference before that and after that. I hate the noise of the VPI but the result is definetly excellent after doing it.
I use a special cleaning fluid from Switzerland, Audiotop. the price makes my eyes wet, but this stuff makes wonders. When I wouldn't have it here, I would not believe it. Vinyl is amazing, when do all right.
I tend to be as lazy as I possibly can. However I practice meticulously Sean's mantra, while every record I wish to play, spins in the cleaning machine.
This thread reminds me of a poster in my dentist's office that reads: "Do I really need to floss all my teeth....only the ones you want to keep."