I have been using TradeX on one site, and it is cheap and OK, but no longer in development.
My favorite now is
Trade Expert 3. It is easy to set up and easy to use. I notice that on the sites where I changed to TE3, traffic and prod. went up. Donīt know why, it just did.
I also use
Trade Pulse. It is just as easy to set up as TE3 and I like the script very much. Support is good there as well, better than TE3 I think, as I still did not get an answer to a question I sent them on mail 4-5 days ago.
Right now, all new sites get TE3 installed. I love the easy Network overview I get there + the fact that I see my sites grow.
Whatever script you chose from these two, you canīt go wrong IMO.