Wi-Fi
Owing to pressure from offspring I just bought a draft n adsl router in the hope of getting better wireless coverage. While it is MUCH better than the old Thomson one (3-5 bars rather than 1 - how's that for science), it can't seem to do big downloads without stalling (eg 90M/B). Only had it a few days so the jury is out. However, as said above, it is also much faster loading pages and worth the upgrade just for that.
Note that this is in a thatched cottage with a bird wire faraday cage to complicate matters.
Think it is worth a go (I got a dlink dsl 2740-r based on magazine reviews).