Oh good grief - too many people to choose from!
Sir Francis Walsingham - one of the people from the Elizabethan age who has fascinated me for a very long time
Kit Marlowe - if only to ask him what of the rumours about him are true
Just about any of the plant hunters, to ask "why?" - but especially Joseph Banks (who sailed with Cook), Richard Spruce (who got seeds of the tree quinine is from out of South America), Robert Fortune (who got tea out of china, and travelled extensively in parts o that country that were technically prohbited to him - apparently by assuming Chinese mannerisms etc he was able to pass himself off as a native of some province distant to where he currently was); and Marianne North (who set herself the target of painting all the flowers in the tropics, and seems to have been somewhat of a keen observer of the places she visited)
To this list I'll add the Victorian photographer Julia Margaret Cameron - it would have to be a week - as her work influenced some modern trends in photography and she shot so many interesting people (including Marianne North).