Although I have both a 3G and iPod Mini.. I'd have to say my Gold Mini is my favorite iPod of all time. I purchased my 3G first and later regretted (when the Nano first came out) not having something smaller. I wanted an iPod with a colored shell, specifically the gold iPod. I purchased the Mini from Apple and have loved it ever since. It always goes to the gym with me and I rarely use my 3G!
The funny thing is: I recently purchased a Touch and decided not too keep it because it didn't do anything special for me like the Mini. After purchasing the Touch, I am in no rush to purchase another iPod. I'm going to wait for one to really "speak to me". Plus, this Mini can last forever!