Biggest Unsolved Problems In Graph Theory ( a la Riemann Hypothesis to Number Theory) I'm not sure whether this is the right place for this question, but what are the most major unsolved problems in graph theory? (Not just a list, but something like a top 10 list or something like that) 
My impression seems to be: 
- Hadwiger Conjecture 
- Reconstruction Conjecture 
- Graceful Tree Conjecture 
- Tutte's Flow Conjectures 
are amongst the biggest. I.e. would gather most superstardom if proved. 

For the sake of providing an answer to this question, Wikipedia has a nice list of (some of) the big unsolved problems in graph theory.
