The first 9 issues were black and white, and supposedly took place between Hulk #6 (first series) and Tales to Astonish #60.  The throughline for those issues was the Hulk's efforts to stop a group of aliens, who I'm blanking on the name of with Rick and an alien named Bereet.  (Then the more continuity minded opted to retcon these issues as "movies" produced by Bereet.)  With #10, they dropped the Rampaging, added an exclamation mark, and moved the action to the present day, in stories that had more or less the same feel as the TV show and that didn't impact on the regular comic (or vice versa).  They were also full color for awhile, until near the end.  The last issue was #27.

Throughout the run, there were various back-ups.  #1-6,8 had Bloodstone, #7 Man-Thing, and #9 Shanna the She-Devil.  Then Moon Knight took over for awhile.  Once MK got his own book, Dominic Fortune took over for the rest of the run.