foreach (var f in Directory.GetFiles(".", "*.dll"))
Assembly.LoadFrom(f);
That loads all the DLLs present in your executable's folder.
In my case I was trying to use Reflection to find all subclasses of a class, even in other DLLs. This worked, but I'm not sure if it's the best way to do it.
EDIT: I timed it, and it only seems to load them the first time.
Stopwatch stopwatch = new Stopwatch();
for (int i = 0; i < 4; i++)
{
stopwatch.Restart();
foreach (var f in Directory.GetFiles(".", "*.dll"))
Assembly.LoadFrom(f);
stopwatch.Stop();
Console.WriteLine(stopwatch.ElapsedMilliseconds);
}
Output: 34 0 0 0
So one could potentially run that code before any Reflection searches just in case.