Norton Commander
Every operating system has a file manager. Microsoft Windows XP has Explorer which can be replaced with the excellent Total Commander, Commodore Amiga had Directory Opus and MS-DOS had Norton Commander. NC (short for Norton Commander) makes MS-DOS more flexible and easier to use for day to day tasks offering a basic graphical user interface for MS-DOS. NC was very popular once but the popularity decreased when Windows 95 was released. Even though the popularity of Norton Commander has shrunk there are still many popular clones of NC on a variety of operating systems. Midnight Commander is a popular clone of NC for Unix-like systems and Total Commander is a modern version of Norton Commander for Windows. Volkov Commander is a modern up to date MS-DOS compatible NC clone.
Cubic Player
Most operating system has a music player capable of playing classic music formats like MOD, S3M and XM. Cubic Player for MS-DOS is the music player to use for listening to classic sound formats in DOS.
Deluxe Paint 2
Graphic packages have changed a lot during the years. Graphic artists of today work in layers but when MS-DOS was popular graphic packages like Deluxe Paint 2 where the defacto standard when making pixel graphics. Deluxe Paint by Electronic Arts was a popular art package also available on Commodore Amiga and Atari ST , but only the Commodore Amiga got version 3, 4 and 5 because it had superior graphics than the competition. Even though the MS-DOS world only got the second version it is quite good for what it is and much better than Paint.
The Draw
The Draw was another art package for MS-DOS. But unlike Deluxe Paint it was used to draw ASCII and ANSI images. We agree that the demand for ASCII and ANSI art has shrunk a lot since the days of MS-DOS but if you want to make a nice login screen for you Linux server and do not want to use an automatic JPG to ASCII converter then The Draw is the paint package to use.
PKZIP/PKUNZIP
Since Windows XP the ZIP file compression system is integrated in the operating system. In MS-DOS PKZIP and PKUNZIP are used for these tasks. RAR is also available but most people remember PKZIP, ACE and ARJ. But do they remember the command line switches?
SEA
SEA was an excellent image viewer so that you could watch multicolor JPEG images in MS-DOS. SEA viewer had basic image conversion tools built in and was a really fast image viewer.
Terminate
Before the internet computer enthusiasts used to dial bulletin board systems, also called BBS. A BBS carried files which users could download and also had forums where users could post topics and discuss matters. To dial a BBS you needed a telephone modem and software to use for calling bulletin board systems. Terminate was regarded as the best terminal program amongst everyone I knew who dialed BBS systems.