Cartoon Network (ended 2000)
Sadly it is "out of print" if you happen to stumble upon one it's either one that has been a "shelfwarmer" or a used one.
I'd go for e-bay, but beware of bootlegs and other rip-offs, prices can go high though....
I myself is lycky enogh to own the first season -bow-set, that blue one....I want season 2 too...those are the best!
Sadly, I don't know any seller myself, If I did I would been all over the person...check closely for used dvds on either amazon or e-bay...someday the real deal pops up...^^
But don't get down, looking and trying to find the dvd's and merchandise or the manga is (what i think) sometimes more fun than actualy having it...yeah, I know, I'm crazy...
Ebay is probably your best bet but it is infested with bootlegs so be careful
I am lucky to own 2 dvd's from the 2nd season and 4/6 dvd's that make up the 'S' season. Those are the DVD's that have like 6 or 7 episodes on it.
For anyone who may come around here in the future, to put in a definitive answer, all of the Official North American made releases of Sailor Moon are indefinitely out of print.
The first two seasons were only ever Officially released by a company called ADV. There were two Blue Box Sets, Season 1 and Season 2 respectively. Each set consisted of 8 DVDs and offered the original Japanese audio episodes with English subtitles.
For images and further info:
Season One - http://www.amazon.com/Sailor-Moon-Complete-Japanese-Language/dp/B000093NPZ/ref=pd_cp_d_2?pf_rd_p=413864101&pf_rd_s=center-41&pf_rd_t=201&pf_rd_i=B0000APVFU&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0MTPK6FYHYWBG32XX02D
Season Two - http://www.amazon.com/Sailor-Moon-Season-Japanese-Language/dp/B0000APVFU/ref=sr_1_1?ie=UTF8&s=dvd&qid=1220862531&sr=8-1
The English Dubbed version of Seasons 1 & 2 was also released by ADV, but never in a box set. This Dubbed version was released in 14 separate volumes.
Vol 1 - http://www.amazon.com/Sailor-Moon-Heroine-Chosen-Show/dp/B0000639E3/ref=sr_1_11?ie=UTF8&s=dvd&qid=1220862589&sr=1-11
Vol 2 - http://www.amazon.com/Sailor-Moon-Scouts-Rescue-Show/dp/B0000639E4/ref=pd_sim_d_1
Vol 3 - http://www.amazon.com/Sailor-Moon-Tuxedo-Mask-Show/dp/B000065AYE/ref=pd_sim_d_1
Vol 4 - http://www.amazon.com/Sailor-Moon-Secret-Scouts-Show/dp/B000065AYF/ref=pd_sim_d_2
Vol 5 - http://www.amazon.com/Sailor-Moon-Introducing-Venus-Show/dp/B000068M9V/ref=pd_sim_d_2
Vol 6 - http://www.amazon.com/Sailor-Moon-Adventure-Girls-Show/dp/B000068M9W/ref=pd_sim_d_3
Vol 7 - http://www.amazon.com/Sailor-Moon-Fight-Finish-Show/dp/B000068M9X/ref=pd_sim_d_2
Vol 8 - http://www.amazon.com/Sailor-Moon-Doom-Tree-Strikes/dp/B000068M9Y/ref=pd_sim_d_2
Vol 9 - http://www.amazon.com/Sailor-Moon-Return-Doom-Tree/dp/B00006G8EP/ref=pd_sim_d_1
Vol 10 - http://www.amazon.com/Sailor-Moon-Trouble-Rini-Show/dp/B00006G8EQ/ref=pd_sim_d_2
Vol 11 - http://www.amazon.com/Sailor-Moon-Ties-That-Bind/dp/B00006JMPP/ref=pd_sim_d_3
Vol 12 - http://www.amazon.com/Sailor-Moon-Wrath-Emerald-Show/dp/B00006JMPQ/ref=pd_sim_d_1
Vol 13 - http://www.amazon.com/Sailor-Moon-Time-Travelers-Vol/dp/B00006L90P/ref=pd_sim_d_3
Vol 14 - http://www.amazon.com/Sailor-Moon-Love-Conquers-Vol/dp/B00006L90Q/ref=pd_sim_d_1
Seasons 3 & 4 were only ever officially released by Geneon Entertainment, and they were each released in two formats, separate volumes and thin-pak boxsets. Season 3 consisted of 6 volumes, whereas Season 4 consisted of 7. Both were released with both English and Japanese audio available as options on the same disc and English subtitles could be turned on if you were opting for Japanese audio. To scale down the links, I will only post the thin-pak boxsets.
Season Three - http://www.amazon.com/Sailor-Moon-S-Complete-Uncut/dp/B00020HBUU/ref=sr_1_1?ie=UTF8&s=dvd&qid=1220863094&sr=1-1
Season Four - http://www.amazon.com/Sailor-Moon-Super-Complete-Uncut/dp/B000244F96/ref=sr_1_1?ie=UTF8&s=dvd&qid=1220863117&sr=1-1
Season 5 was never officially released on DVD for North America.
All other sets out there are bootlegs in some way, shape or form. Some are burned copies, others are factory pressed DVDs, however they would be manufactured in foreign countries overseas either where there are no copyright laws (Taiwan) or simply where they could care less (China). I'm not for or against bootlegs, but anyone who's looking to buy something should know the facts before they start looking, as many people/sellers will claim that their bootlegs are official releases. Know what you're buying for what it is so that you won't complicate things later and be disappointed. Finding copies of the out of print official releases can be a challenge, and can also empty your pockets completely, so sometimes a less expensive alternative is not such a bad idea. Just be prepared.
I Could say Blockbuster but i have no idea if its there anymore... cuz i was like 6 when i saw those dvd's... but if u dont see them try Walmart, Ebay, Craig's List or Target.