Debian Testing is an excellent Linux distro, very up-to-date, and has more packages and supports more architectures than any other. Here are suggestions for desktop setup:

• Google Chrome.

• Pale Moon. This is a repackaging of Firefox which is faster and a bit leaner, still very compatible with everything Firefoxy.

• Java. Try this:

sudo sh -c 'echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" >> /etc/apt/sources.list'
sudo sh -c 'echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main" >> /etc/apt/sources.list'
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EEA14886
sudo apt-get update
sudo apt-get install oracle-java8-installer

• Compile a new kernel optimized for your hardware, for a jolt of speed:

https://www.debian.org/releases/stable/i386/ch08s06.html.en

• Recompile glibc optimized for your hardware, for a big jolt of speed:

http://notes.ponderworthy.com/rebuild-glibc-optimized-for-your-cpu-in-debian-testing-as-a-local-package-version

• Add grub-customizer to change the kernel to load by default, if desired: