which DSLR

hi
i am new to this forum and wonder if any one can help.
i have a canon 400d which i enjoy using and get good images, however i would like to upgrade to another canon possibly the 40d 450d or the 500d
i do not need video
what do you recommend

thanks

How much do you shoot - ie: how often and how many frames do you usually take.
Why do you want to upgrade.
What's holding you back with the 400d

the camera comes with me to work every day and i probably take around 30 /40 snaps each day
yes i am happy with the 400d but i supose the main reason for upgrade is to have a larger veiwing screen and higher iso

thanks

try using the hacked firmware, it allows for higher iso.

How often would you be using anymore than 1000 ISO.
Unless you were using it for more than 95% of your pics, I wouldn't bother doing the upgrade.
It doen't seem like anything's holding you back.
The three bodies you're considering won't give you that much benefit.
By wanting higher ISO, it sounds like you just need more light. Put some money into faster glass.