Of those uTorrent would be the best choice. It has all the basic features needed for bittorrent and is the smallest and uses the least amount of resources. They also have great support with their guides, forums and help file.
Since BitTorrent bought uTorrent, their client is identical, but BitTorrent adds the unnecessary program DNA to its download. DNA is always running, uses more resources than the bittorrent client and does nothing for the average user.
Deluge uses a pretty good amount of RAM and is missing some of the features that uTorrent has.
I have not used Shareaza, but there is a fake one out there and if you are not using Gnutella or eDonkey, it probably is not a good standalone bittorrent client.
http://torrentfreak.com/the-shareaza-conspiracy-in-a-nutshell-080313/
MiniNova is a torrent search site (good one), not a bittorrent client.
Best Free BitTorrent Client
http://www.techsupportalert.com/best-free-bittorrent-client.htm