whats the best fluid for long lasting Lps.

LAST is the stuff to use. But should be used only on totally clean (cleaned) LPs.
I have purchased used LPs coated with LAST and they ARE BETTER.
I would pay a buck more per used LP for LAST coated LPs.
(Which is about what it costs to do them with LAST.
Other than that use the LAST stylus preservative. Every LP side a dab of it. The stylus will last way longer than without it.

to rushton and elizabeth,thanks,and where do i get the disc doctor and does it act as a laster for lps.i have a full gallon of nitty gritty pure 2, is it good compared to disc doctor.

http://www.discdoc.com -- Disc Doctor just cleans, it does not change the vinyl nor does it add a coating to the vinyl. I've never used the Nitty Gritty fluid, so I can't compare to it. If you want something that act as a "preservative" on the vinyl, use LAST.
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thanks rushton.pat

I agree with Rushton that a good cleaning is all that is really needed. (But what constitutes a "good" cleaning is a whole other discussion!) The environment is inherently dirty with dust etc. so using a preservative will just "preserve" in the grime that you didn't remove. I prefer to not have anything between me and the grooves!