Theatre or theater? 

I prefer American spellings to British ones (“humor” over “humour,” “center” over “centre,” “judgment” over “judgement”), so theater has a native appeal to me, and theatre seems affected. 

But I’m getting over it. 

As it is, the usage is not consistent among theater/theatre companies in the U.S., though professional companies are more commonly using “theatre.” 

Some like to apply theatre to the art form and theater to the building.  Thus,

There should be more national support of theatre in the U.S.

but

The theater on Main Street is being painted next week.

This distinction has no formal support—standard dictionaries do not acknowledge it.  I find the distinction compelling, however, because it enables the language to do some fine tuning, and I like to take advantage of such opportunities.  Synonym distinctions, for instance, when observed, empower the language significantly:  it is useful to distinguish between artificial, synthetic, spurious, and specious.  In this light, I welcome the distinction between the building in which plays are performed (the theater) and the genre of drama (the theatre).  I want people to know what I am getting at when I write:

That’s some noisy theater!

and

That’s some noisy theatre!

Without those semantic distinctions, however, I don’t see the point in using theatre, and I am not comfortable seeing theatre used in both senses:

Acme Theatre Season Opening

and

We are soliciting donations to support the restoration of our main theatre.

I would prefer to see theater in that second sentence.