As many others have noted, we'll all give you a different list. (Mine follows.) But too often new pipe smokers are told to start out with aromatics, which I think is a mistake. In my experience, aromatics are the most disappointing blends out there, as they often don't taste much like tobacco and they almost never taste the way they smell. So my recommendation would be to avoid aromatics at least until you've tried a number of different non-aromatics. And, as others have also said, your best bet is to smoke widely; trying a wide variety is the only way to discover what you like and get a handle on what each different type of tobacco leaf offers.
So whether you go to a local tobacco shop or order online, I'd recommend trying any of the following (mostly!) easy-to-find blends, just to get your feet in the water:
English (with latakia): Dunhill's Standard Mixture, Dunhill's London Mixture, GLPease's Westminster, Esoterica's Margate
Balkan Blends: McClelland's Grand Orientals: Yenidje Highlander, GLPease's Caravan
Oriental Blends: Presbyterian Mixture, Rattray's Red Rapparee, Robert McConnell's Oriental Mixture
Virginia Blends: Rattray's Old Gowrie, Rattray's Hal o' the Wynd, GLPease's Embarcadero
Virginia Flakes: Samuel Gawith's Full Virginia Flake, Rattray's Marlin Flake, Butera's Royal Vintage: Matured Flake
Virginia/Perique Blends: A&C Peterson's Escudo, GLPease's Haddo's Delight
Virginia/Burley Blends: Esoterica's Stonehaven, Solani's Aged Burley Flake, Gawith and Hoggarth's Bob's Chocolate Flake and Best Brown #2, Samuel Gawith's Best Brown Flake
There are also some wonderful blends that include more than a little unflavored cavendish -- I call them Scottish blends, but that's not universally accepted -- which gives them a roundness, sweetness, and depth of character that I just love. It's an awkward category, but I'd include in it: Rattray's Jocks Mixture, McClelland's Anniversary, and Esoterica's And So to Bed.
Of course, these are just my personal choices. And I could probably have given you 20 different ones.