OR
You're forced to form your coalition after the election in proportional representation systems like you often see in European countries.
I prefer the former to the latter because it forces the parties/candidates to answer much more specifically about what their policies will be if elected. In the latter systems the largest party might have to roll over and give up policy making on this key issue or that in order to bring a minority party into the coalition so as to achieve a minority. That really sucks if you voted for that larger party thinking they were going to have one policy on an issue that was really important to you only to see that handed over to another party you did not vote for which might have a very different policy than the one you wanted.
and yes, I know politicians frequently lie and break their promises to voters and do not do what they said they were going to. That's true in all systems.
oops. I meant to say “so as to achieve a majority” in the 3rd paragraph, not so as to achieve a minority.
FLT-bird “I prefer the former to the latter” — and you’re right.
Otherwise one ends up with horse trading.