By David Welch
Few doubt that General Motors is the strongest domestic auto maker. Among the Big Three, its plants are the most efficient, its cars have the best quality, and it's the only one that has been reporting solid profits in recent quarters. And unlike Ford Motor (F) and DaimlerChrysler (DCX), GM (GM) has held the line on market share. But being the best of a trio of troubled companies doesn't necessarily make GM all that great.