How about 120GB
1 Python 3.4 and PyScripter..
2 Web Tools(Dreamweaver,, FileZilla and Xampp)
3 Java and an IDE
4 Graphic Tools.. Paint.net and Gimp
and other general stuff.. email client etc..
Overall I can live nicely with just 120GB's
In other words it simply boils down to what you need individually which varies automatically from person to person, PC to PC when having multiple systems as I do here in contrast. If you beta test softwares and the next person only dresses up a few images and checks the mail there's a vast difference in what will be considered "Adequate" drive space available where one will suffice easily with a small SSD while the other will need a bit more space on the OS drive as well as for storage and backup purposes.
With the ongoing dual boot here I also run multipe VMs which are stored as files on both the host drives and backed up on one of the two main storage drives as well as having just added on a fal cooled usb/eSata enclosure now seeing one of the previous 1tb backup drives finding the drive previously thought to be having problems may have been the sata port on the board while likely a cable in need of replacement since the drive is functioning like new! Eventually when set up by way of eSata it will be seeing a new larger capacity drive like a good 4-5gb for a start!
Now why that big of external drive? Well besides images from the OS drives on each desktop and laptop just imagine an image made of the 2tb drives being stored as well as all system images dedicating it for that purpose leaving the other drives as fluid for both long term and temp storage. Having a larger drive of that size can also be moved from pc to pc which can make things a bit easier for file transfers since when compared it takes less time for file copying from a drive in a usb enclosure then transferring by way of a larger flash drive with the comparison being made with a 128gb 2.0 flash drive to the 1tb WD Green energy efficient not performance type drive. The Kingston Data Traveler model isn't the same as you would get from the Hyper X series performance line of that brand. The test was actually unintended when seeing files transferred to the new 10 laptop while most often a smaller 16gb USB 3.0 drive will suffice.
One thing noticed immediately when going to add a new drive in 10 compared to how 7 is was that the Disk Management was quite a bit more prompt when called up and seeing a drive letter change made. Instead of seeing E, F, G letters taken up leaving those open the mini tower's external drive was given the K for Confidential. The new fan cooled model on the main build also saw that letter change as well while the 1tb will still be only the temp addition.