I am a designer, so for me anything anyhow connected with visual aspects.

Someone already posted about old coins and film photography so I will add:

· Watching Movies — at least once for the story and overall feeling, then for the story again and visuals, colors etc., later for techniques, ideas, framing, music, rhythm, cuts and so on.

· Stamps (Philately) — what more can I say, sometimes I forget about my unsegregated albums, but when I reopen them or find something to add, I am gone.

· Collecting well designed magazines and other printed materials — this one was a big one for me, for a long, looong time. Still, from time to time I will find a great business card or a catalogue, as they are becoming scarce now, or in the ocean of very poor design — it always feels like finding a real treasure.