My wife and I go shopping with each other all the time. She values my oppinion which makes me feel special; I love seeing that twinkle in her eyes when she she finds something that makes her feel sexy... it's a win-win. I also love seeing her in something I've never seen before.
I always buy her lingerie... she's very cheap, and I love the feel of expensive satin and silks. She enjoys wearing fine lingerie and knows I'll spend the money for it when she won't, so she's content with me doing her shopping. Would I love to be surprised by her showing up in lingerie I've never seen? Let's see... the last time she did that, she came around the corner with some Winnie the Pooh flanel pjs. I laugh at them and refer to them as her 'not tonight' wear.