I'm a little late but would like to contribute while (hopefully) this sub grows. I've only recently gotten into Spirit Island but I really like it, even though I've been getting whooped. It hasn't quite clicked for me yet. My favorite right now overall is probably Hadrian's Wall though.
When I used to travel around the state more for work I always kept Palm Island in my bag. This was the perfect game for me situationally since I could play a round or two in my truck if I arrived somewhere too early. I'm really looking forward to getting my copy of Palm Laboratory.