Approaching Scafell Pike from Wasdale Head in the west, Wastwater is a beautiful lake and Lingmell Beck a pleasant river. Once you start to climb, you can take the interesting Corridor Route which crosses streams in a couple of places. Alternatively the Sprinkling Tarn and Great End route is rockier, but with great views on a clear day.
The longer walk from Borrowdale to the north can climb alongside Grains Gill from Seathwaite. This is a pretty stream and would naturally lead onto Great End.
You can also approach from Hardknott Pass to the south. From memory, this is rather marshy and less dramatic.
If you're in the UK, check out the Ordnance Survey Maps layer on http://www.bing.com/maps. Or if not, Open Street Map has less detailed coverage, see http://www.openstreetmap.org/#map=13/54.4401/-3.2480