I've got the htc thunderbolt with verizon. Some things I've done to personalize it:
Light grid pro live wallpaper, did pay for it, but believe in sporting the impressive developers. Plus, it's fun to create my own themes. (on newer models, live wallpapers do not kill your batt life like they used to. 3% of my usage on average)
Swype keyboard. I love it, so much easier on my hands, though I can get some funky misspellings.
Just arranged the home pages to make sense to me. I still have one blank one which will be game widgets-probably in scrolling icons. The others are: main page with texting program, internet browser, gallery and camera, weather widget, "note me" app, facebook app. Next page to the right is texts, don't know name of the widget but I like how you scroll thru conversations. The next page is calendar. first left side page is friendstream but don't use it much. Last page to left of main home screen is quote of the day widget, pulse news feed, and widget for pandora internet radio.
For texting I use handcent and love the customization. Can change fonts, speech bubble colors, etc per each person you text.
Dearly waiting for a chron of horse newsfeed/discussion forum app! Then I truly would get nothing done!