When I first transitioned to raw foods, I relied heavily on spinach as the green in my diet, especially for green smoothies and juices. I took some time to acclimate to the taste of stronger greens, like kale and collards, but as I ate more of them, I found myself craving them more and more. Greens are now the foundation of our diet, and rotating our greens allows us to get a wider variety of nutrients. I'm not really sick of spinach, but I do like to include other things.
If you've had your fill of spinach, try some of these in your juices, smoothies, and yep, even salads, though some of the tougher greens would need to be massaged and/or marinated for salad purposes.
Mache (or Lamb's Lettuce)
Red Leaf Lettuce
Green Leaf Lettuce
Basil, Cilantro, and other Herbs
Search your local produce section or farmer's market and see what greens you can find to mix it up a bit.
BTW- My 11 year old daughter and I went to the doctor together today, and the nurse was surprised to find that our blood pressure measurements were within a few points of each other. Thank you, raw food!