Kids up until age 2 are four times more likely to die or be seriously injured in a crash if they are forward-facing.
Everything else I would have posted has already been posted--the links to the crash test videos and other statistics, and the recommendations. Britax Marathon or one of it's 65 pound weight limit clones is the first choice, the extra $$ goes towards more comfort, more features and an extra 2-3 years using the harness. Most kids don't outgrow it until age 5-7. Most kids outgrow Graco convertible seats at age 2-3, Evenflo and Dorel (Cosco, Safey 1st and Eddie Bauer) at 2-4.
Second choice would be a Cosco Scenera for $40. It rear-faces to 35 pounds, forward-faces to 40 pounds, lowish top slots, but overall a great seat.
So you'd use these convertibles rear-facing to their limits and then forward-facing to their limits. With the Britax you would not need another forward-facing seat later, with the Scenera you would go with the Graco CarGo or Evenflo Generations later if your child doesn't need the higher harnessed weight limit, only the taller top harness slots.
There's also the Fisher Price Safe Voyage Deluxe, a clone of the Britax Marathon with a few missing features. It harnesses to 55 pounds and has the same top slot height though, so it's an awesome seat for the price.