We had a successful coalition for the early 1930s as well.
I am not so much interested in seeing an attempt at coalition government
(although I do believe that weaker governments electorally speaking lead to better, more scrutinised and less extreme legislation - governments that have large majorities become elective dictatorships and can ram through any old crap they like, we have seen it many times)
I am more interested in a Hung Parliament as a vehicle to comprehensive electoral reform, which this country badly needs. If people want to see a re-engagement with politics in this country, the best route to that is to make people's votes actually count for something meaningful, not just those people who vote in 10% of the constituencies at most.
I don't think we need to go to an extreme form of PR
like in Israel where the single issue parties often have the balance of power, but we need to much more fairly represent the smaller parties in terms of seats - it's ridiculous that it takes on average 15,000 votes to elect a Labour MP, 20,000 for a Conservative MP and over 100,000 votes to see a Lib Dem returned, and even worse for the smaller parties. That's a sure-fire way to disenfranchise a lot of people.
Our electoral system is manifestly unfair. The Conservatives have no interest in changing it. Only a Lib-Lab government whether in formal coalition or not, with electoral reform one of the conditions of support, is the only way this ridiculous and unjust situation will ever change.