Convert/Merge multiple videos to single avi

Dear forum,
I am newby and I need to convert and merge multile vidoes to a single video.
At the moment I am doing so with Freemake, do you have any suggestion for better software which ideally:
- Accept multiple input format but at least .mpg/.3gp
- Multile input file
- Output to common compressed formats (single file), compatible with set to boxes (is XVID the best for compatibility?)
- Allow a little of configuration, like resolution and stuff like that, I dont need (and dont want) huge configurability
- Easy to use

A plus would be:
- Some fading effect between videos
- Accept as input Everio .mod files (but I can always rename them to .mpg as I do now so it is not a problem)
- Fast :)

Any suggestion?

Many thanks!