The ones @bwhite220 posted are great and amazon vinyl is probably the most consumer friendly. There are a few others that are decent too (some are out of the US but still have great selections).Most of my NEW vinyl comes from Amazon. They have a huge selection (as usual) and they are one of the only places I know of that will replace an album if it is damaged/scratched/warped. Every other big box retailer of any kind state that all vinyl sales are final and they don't take care of their stuff.
I also love SMLXL Vinyl.
Then, there is also a subscription service called Vinyl Me, Please. They send a monthly album to all their subscribers and you end up with some stuff that you've never heard of but end up loving. I had a subscription to them for about 2 years.
http://www.metrowax.com/
http://www.insound.com/
https://boomkat.com/
http://vinylloop.com/
https://www.juno.co.uk/
http://www.downtown304.com/
https://www.decks.de/