He was obviously incredible. Grab yourself a Marvel Essential Tomb of Dracula - the fact that they are in black and white is good. The art is amazing.
I remember a couple of years ago when Colan did that Captain America special, Marvel offered the standard version and a black and white variant. I bought the variant, obviously. Given that he was an octogenarian with eye problems, some of it was predictably rough, but there are parts of that comic which were still incredible. Get a copy on ebay, it's worth a look.
Why Night Force #12? That cover. I picked it up from the newsagents back in the day - I must have been about 11 years old - because it was just one of the random haul of American comics which had turned up that particular month.
I had no other issues of Night Force, but the cover really unsettled me, so I bought it. It's the nutso second part to a story about The Beast from The Book of Revelations, rumbling through a 1920s funfair killing people. I always thought the cover was the view of someone stuck at the top of a ferris wheel. It stuck with me, and it was the first thing that came into my head when I heard Colan had died. Great artist. RIP.