Probably a little late in response, here, but....
My "death grip" lenses are the Zuiko 100/2.8 and 35/2.8. These are the two lenses which I started out with Olympus on in 1986 and they are still my all-time favorites.
The OM-2S is the only "real" OM body with continous-reading spot-meter functionality. The OM-3/3Ti, 4/4Ti bodies will do the same, but only after you have pressed the spot-meter button once and then they only give you a floating dot. The OM-2S, in manual mode, has the bar-scale match-needle display showing the spot-meter reading in real-time.
No OM kit is complete until you have the OM-3Ti. It's a disease, really.
As to size, I know there is a fascination with pancake lenses, but the length of the 35/2.8, 50/1.4, 24/2.8, etc., are just about perfect because when you lay the camera in your left palm the aperture and focus rings fall perfectly in place. With the pancakes your fingers want to go beyond the nose of the lens and will end up in your picture. In fact, with the 24/2.8, I still suffer this problem so I use the matching lens shade, not for shading, but for keeping my fingers in place.
Oh, and as to completing the kit with an OM-3Ti? Hahahahaha... There's always something more. You'll be collecting all variations of each lens.