I would recommend you ask a senior at your dojo or your sensei about videos, for this reason:
The fact that you are asking implies you are new enough to Aikido that you don't already know what you are looking for in a tape.
Which means you might go with what someone here suggests, which may not be very similar to the style your sensei teaches. This will only confuse you. I don't mean by this you shouldn't see as many different styles as you want (I personally really like learning a new/different way to try things)...
But I've seen students before get really worked up and anxious when after a few weeks of Aikido they come across a book or tape that shows something different. Who to believe!