Yes, Staedtler Mars is a very good brand. I use a wide assortment of their technical pencils with various leads & thicknesses. I'm crazy about their black pigment liners and have a ton all over the place for convenience. They're even good when they're semi dried-out. Their white plastic erasers are THE absolute best, to me.
Also crazy about Prismacolor pencils. Have used Prisma designer markers for years including some other old brand of horribly toxic smelling design markers (AD? Letraset? another one? Drawing a blank. I can't remember, I finally threw a big box of them out because I was worried they're too dangerous to use).
I hardly ever use color markers anymore since I started using a digital tablet in earnest, but I do use the Staedtler ink liners and Prisma color pencils still.
Are you talking about regular pencils or colored pencils? There are many great pencils out there to choose from and I think that you have to try a lot of different pencils until you find the one that fits your style the best. For me, I personally like wooden pencils from Mitsubishi Uni or from Tombow (both are Japanese companies). Mitsubishi and Tombow both offer great quality and a wide variety of lead hardnesses.
I recommend JetPens (http://www.jetpens.com/), it is a great site where you can browse through many different pencils and pens and read other people's comments on them. Jetpens has a wide selection of goods but they are a little expensive (I live in Japan and for most of their Japanese products, they are not quite double the price) but their customer service is supposed to be topnotch and they do carry many items that would be difficult or impossible to find elsewhere.