As far as life expectancy, hepatic (liver) cancer seems to be the worst -- either from hepatocellular carcinoma or metastatic spread to the liver.
As far as deadliest, pancreatic, esophageal, gastric, and hepatic all seem to be uniformly fatal.
Contrary to popular belief, most lung (except small cell) and brain cancer (except glioblastoma multiforme) aren't that aggressive and usually don't kill as quickly as people think. Depending on the stage of diagnosis, many can be cured with good 5 year survival rates.