MAME Frontends
DOS MAME runs off the command line, i.e. you have to type in a command to run a game...not much fun!
There is a huge variety of MAME frontends on the web, some excellent and some in developement :)
AdvanceMenu is my first choice of frontend
My PC does not have a useable keyboard, it doesn't boot into Windows and the PC components are mounted inside a JAMMA cabinet
The cabinets joystick buttons and coin mechenism are connected directly to the PC via a J-PAC keyboard encoder
For me the beauty of AdvanceMenu is that it allows you to reconfigure virtually everything to do with the frontend, including the keys to navigate through the system
This is vital for my setup as I do not have a keyboard!
Another DOS based frontend worth mentioning is ArcadeOS from the ArcadeOS team. This has slightly more features but currently seems to be struggling with the newest MAME beta's - its nice though :)
If you run Windows9x/ME in a normal PC, Emu Loader is a good choice for running DOS as it is nice to use and very configurable. Emu Loader also allows you to display both screen shots and flyers. You could also run the DOS frontends in a Windows DOS window too