I’ve needed this a few times in the past and figured I best note it down for my own reference.

If you have created a number of objects and you want to be able to compare them during debugging, you can assign an Object ID to each instance of the object in the watch window like this:

Once assigned, you can evaluate that particular object instance either in the watch window or in the expression evaluator:

(The above images have been pilfered from Jim Griesmer)