Erik Kirschbaum- Erik Kirschbaum is a Reuters correspondent in Berlin. -

Has this been dullest German election campaign in decades or the most exciting?  Has the battle for power in Berlin between Chancellor Angela Merkel and Foreign Minister Frank-Walter Steinmeier that concludes with Sunday's election been a memorable showdown or a forgettably boring contest?

Many journalists, pundits and voters have complained it's all been a merciless bore compared to the high-octane battles of the past with little action and precious few highlights.

But I would argue that in many ways it has been one of the most interesting campaigns in decades. Why? Because the outcome is so uncertain and there are more different government possibilities that could result from it than at any time in Germany's post-war history.

Instead of the usual centre-right or centre-left choice that German voters had for the last 60 years, there are options galore this time -- at least in theory.

There could be a centre-right government, another grand coalition or several three-way coalitions that could include the Free Democrats, the Greens and from a purely  mathematical point of view even the Left party that have never been tried before at the federal level.