Johnson & Johnson ( JNJ) In April, Johnson & Johnson bought medical device maker Synthes for $21.3 billion in the biggest merger in its 125 year history. The purchase added to a run of eight other crisis-time acquisitions over $250 million in size that's brought its deals total to $25.2 billion. With Synthes, Johnson & Johnson took over a high quality maker of medical devices like screws and bone grafts, bolstering a health products unit that has recalled over 50 products since 2010, according to Bloomberg reports. Currently, J&J is the second largest maker of health products to Pfizer. While J&J's underperformed its drug and medical products competitor, gaining just 5% year-to-date compared with Pfizer's 13% return, the company's shares are only down 10% from its pre-crisis highs in contrast to Pfizer's near 30% loss. Even after the deal, Moody's maintained J&J's AAA rating. In total both Pfizer, with its $68 billion acquisition of Wyeth and Merck's ( MRK) $41 billion takeover of Schering-Plough in 2009 have cut larger deals than J&J, but neither has bought many other companies. In 2010, Merck ended an $8.2 billion animal health services joint venture with Sanofi Aventis ( SNY) over complications to the deal like divestitures.