Find Item in ObservableCollection without using a loop

Here comes Linq:

var listItem = list.Single(i => i.Title == title);

It throws an exception if there's no item matching the predicate. Alternatively, there's SingleOrDefault.

If you want a collection of items matching the title, there's:

var listItems = list.Where(i => i.Title ==  title);

I Don't know what do you mean exactly, but technially speaking, this is not possible without a loop.

May be you mean using a LINQ, like for example:

list.Where(x=>x.Title == title)

It's worth mentioning that the iteration over is not skipped, but simply wrapped into the LINQ query.

Hope this helps.

EDIT

In other words if you really concerned about performance, keep coding the way you already doing. Otherwise choose LINQ for more concise and clear syntax.