Notebooks and notbook covers / holders. If it looks nice (aka not cheap) I will use it a lot. If it is refillable and looks good I will use it forever ... or until I get a nicer one.
I also enjoy Pens which provide entertainment. I have a Pen from CDW which as you turn it, part of the logo goes the way you are turning the pen,m and some of it goes the opposite direction. When in a boring meeting I liek to play with it. Because of this valuable BONUS function I take it with me often.
If you have real money to spend, I would spend it on CONTIGO coffee and water bottles. In particular the ones that only take a finger to operate. Everyone will use it and brag about it.
If your customers are beer drinkers. I know a cool bottle opener which will impress also.
My company gives out a delicious bottle of beer, and people LOVE it. We're memorable, and I guarantee, people remember the experience. Best part, we get follow up conversations, which is the whole point.