Turns out that "girth" is what my wife needed take her over the top. We've played around with different size toys (along with the occasional cucumber). I think our problem in the past is that when we thought of using something large, we usually went overboard.
We'd been having success giving my wife some good orgasms with average size dildos and with my average size cock.
My wife's sex drive has improved dramatically over the last several months (update from my profile).
Update: March 2016 - My wife has been a total cock hound lately! I have no idea what has changed, but I hope it doesn't stop. We've been having intense sex every weekend - Friday night, Saturday morning, Saturday night, Sunday morning… AND she no longer closes up shop after my first orgasm. Instead, we spend some quality time with a nice fat dildo until I'm ready for round two! and round two lasts until I'm physically exhausted. I think we've fucked more in the last 4 weeks than we did in the last 4 years! She's also starting to get into the "GIVING" side of oral and anal pleasure - YIPPEE!
A couple weeks ago I suggested we pick up a nice dildo with a little more girth - nothing terribly extreme - just a nice fat cock (7"x 2"). After rigorous session of lovemaking, my cock needed a break to recover from orgasm. After a little clean up, we engaged our new toy for the first time. I took it slow and easy to make sure the new girth was acceptable for more rigorous action. It didn't take long to see that she was enjoying the feeling of being stuffed VERY much! I tried to stay focused and make the strokes mimic the speed and force that work best when we're screwing. It only took a few minutes to bring her to the most convulsive orgasms I've ever seen her have. Her bucking and contractions made it a real challenge to keep dildo from pushing out and flying across the room! A few minutes later she had another orgasm that was equally intense. A couple more times and she made me quit.
By this time I was hard again and ready to get back in the game. My initial concern was that after being reamed out by this fat cock, my skinny cock would just be kind of bouncing around inside her. I was absolutely wrong. Her pussy was clamped on my cock better than ever and we fucked like crazy until both of us were both too exhausted to continue.
We didn't talk too much about the following week - talking about sex is still a hurdle we are working on. While I knew she enjoyed it, I wasn't sure if this would be like some other toys where they only get used when my wife is feeling "extra" naughty. I was delightfully surprised when my wife had it laying out the next Friday night and again Saturday night. Apparently she enjoys the intense orgasms 😃 I enjoy being able to keep the action going while my cock rests for round 2.
Since I'm confident that she enjoys the fatness of it, I went ahead and invested in higher quality toy and a high end harness designed for men to wear. I can't wait until they show up!
http://www.vixencreations.com/collections/vixskin/products/maverick?variant=1662172804
https://www.myspare.com/product/deuce
Another perk is that with her growing comfort level with toys - she has taken more interest is using them on me as well. I'm hoping that once she experiences it with our new harness, she will consider letting me order a harness for her to wear 😃
As for me, I enjoy more girth for something stationary, like a butt plug - but for in/out action I prefer something slim that moves in and out without a lot of resistance.