The secret to great pasta is obtaining a balanced ratio of sauce to pasta. Too much sauce sticking to the pasta will overpower the pasta, and too little sauce sticking to the pasta will make for a bland and "doughy" dish. I've found that linguine provides the best sauce to pasta ratio. The flat linguine provides the right amount of surface area to which the right amount of sauce can stick. Spaghettini (thin spaghetti) is also comparable in its noodle mass to surface area ratio.
Regular round spaghetti has less surface area for a given mass of noodles, and so not enough sauce is able to stick to the noodles, giving it a slightly doughy flavor. Other pastas susceptible to this are fettuccine, penne, and rigatoni. The exception would be when making a baked casserole, where the sauce and flavor would have an opportunity to be baked into the pasta, thus overcoming the smaller outer surface area. Undercooking the pasta and then sautéing it briefly with sauce also help the sauce cling to the pasta (sautéing with a bit of water used to boil the pasta helps too). Pastas such as angel hair and capellini have too much surface area, and are overpowered when using thicker sauces, but do better with lighter sauces.
The linguini that I like best is DeBoles Linguini, which is made of durum semolina and Jerusalem artichoke flour.