A couple of weeks ago for our 1 year anniversary Yuko, her sister, mom and I went to Kagawa Pref. for some udon. The udon in Kagawa is famous nationwide and is called Sanuki udon, the pre-Meiji Restoration name of the Kagawa area. So, we drove 3 hours eachway just to eat some noodles. Yes, they are that good! We went to two shops.
Ueharaya Honten 上原屋本店
Udon from ¥220
Ueharaya is located on an alley near Ritsurin Park, great if you're going to see the park. You go in, line up, order your noodles and take what ever tempura you want. Behind there there's a institutional coffee pot looking thing that has the soup broth in it. You put it in your self. There's also a station where you can cook your noodles some more if you want. Their Korokke is pretty good too!
Suisha Udon 水車うどん
Udon from ¥420
Niku udon ¥840
I liked this place the best. The noodles were fresh and meaty. Like you really had to chew into them. I got the Niku udon and it was so good. If you're heading to Konpira-san try stopping off here.