This year's German general election, scheduled for next Sunday, is similar to the two most recent such elections in at least one respect. The Christian Democrats (CDU) have gone into each of those campaigns with a significant lead in the polls, only to see that lead either shrink or disappear by election day.
The CDU's leader, Angela Merkel, is currently the chancellor (head of government) heading up the so-called "grand coalition" government with the second largest party, the Social Democrats (SPD). If she had her druthers, Merkel would instead form a government with the Free Democrats (FDP), a smaller party to which the CDU is ideologically closer. In 2005, the combined number of seats won by the CDU and FDP was not enough to constitute a majority.
Up to now, with the CDU leading in the polls, and Merkel personally popular, the consensus has been that Merkel would remain as chancellor, and the only open question (not an unimportant one, but one that doesn't lend itself to electoral drama) is which party(ies) would be included in her new coalition.
Now, this report from Time seems to indicate that the situation is so volatile that Merkel could lose the chancellorship to the SPD's candidate, Frank-Walter Steinmeier, although that still seems unlikely.
Here is an opinion piece from the English-language edition of the German newsmagazine Der Spiegel. Writing from a left-wing perspective, Dirk Kurbjuweit criticizes coalition-building among ideologically disparate parties. He instead advocates something that the SPD has until now ruled out, a coalition with the Left Party, which is a combination of eastern German ex-Communists, and western German defectors from the SPD. I don't share his ideology, but I agree that parliamentary democracy functions best with a strong government, and a strong opposition party, facing each other in the parliament. A grand coalition of the two largest parties detracts from that.