Chameleon is a choice of many since it has a fair database that updates on a regular basis (in regards to all Chameleon products). Speaking of Chameleon Submitter itself, there are currently more than 2000 TGP/MGP sites to go with, all set up in 192 categories.
New sites are being constantly found by crew of Chameleon Submitter Team and sites that arrived via Suggest form are also being added into the Database as long as they meet the basic criteria. Chameleon Submitter Team checks up all the individual sites and every single one is set up according to its site rules which finally makes a big difference..
You can naturally fully customize the database which is appreciated and often expected..
The tool itself is clean, easy to operate, fast, and pretty user friendly. The learning curve is minimal and its generally found to be the easiest tool out there in the market.
Lets not forget that choice of submitter is mostly a question of personal choice. However, no matter what submission software you take, it is always gonna be just the tool - wont make miracles unless you know how to do them. Chameleon is well done and has all you need though - its gets the job done and helps a lot to achieve your goals.
Take a look at these official Tutorials for Chameleon Submitter, there you can see how to work with the tool properly and how does the software actually look like/how to make maximum out of it.. Its been made in Macromedia Flash, you can download it here:
http://www.chameleonsubmitter.com/tutorials.php