I use a Dell Streak.
- 5" Screen
- StreakDroid Custom ROM (FroYo 2.2.2, soon to be upgraded to GB 2.3.4)
Custom ROM runs nice and fast. I'll get reboots if my battery dips below 15%, but I can go a day and a half with moderate usage on a single charge. I don't use a ton of apps, rarely have GPS turned on. but web surfing on a 5 inch screen beats every other phone I have seen.
I'm hoping to get a Samsung Note, 5.3 inch screen.
Soooo. What do you have?