Concerning wildlife, my next lens that I want (and it's going to be a while) is the
Panasonic Leica 100-400 F4-6.3. On the Micro 4/3 format, (Panasonic and Olympus cameras, mine is the Panasonic G9) Focal range multiplier for the format is twice that of the 35mm (Full Frame) standard, which means an effective range of 200-800mm. It looks incredibly useful for wildlife photography, because equivalent lenses on other systems are so big and bulky (and expensive) as to not be practical.
This one, at 6.75 inches (171.5 mm) long and weighing just over 2 lbs, means you can take it with you in most camera bags. Being made to Leica's standards, it's also has excellent image quality, considering the focal length. The only problem I've been reading about is a stiff zoom mechanism, but apparently that can vary from copy to copy.
As you can tell, I really want it
. Especially after seeing
Terry Lane's video on YouTube.