What are the best ports to be used in µTorrent?
Talking about uTorrent you might want to check out a couple of tips in the following MakeUseOf article.
10 Ways To Speed Up Torrent Downloads
Higher ports are better, between 40000 to 54000
In general any random port above 10000 will do. I also recommend to set Protocol encryption to forced.
But it's always a good idea not to overlap with IANA assigned ports just to be sure it's not interfering with any of your other applications. http://www.iana.org/assignments/port-numbers
In case your provider is trying to block Torrent it might be good idea to actually use some ports assigned by IANA. Trying to slip through...