heh, imho
you must know whats your preference before going single stompboxes. If you not sure, just get whatever been sugggested in all the responses. Coz if you dont know what you want, even if you anyhow buy anything, you will have to know how to incoporate into the music you are playing. If doing original, any effect can be a tool and whats important is the person utilising the tool, not the tool manipulating the person. And if you into playing covers, the best is also just get everything and anything cos you can do any style/sound you wanna
and always remember, single stompbox is not analog and analog is not single stompboxes. There is no relation to being single stompbox being analog. Its the circuit inside and components that decide, not just being a singlestompbox format.
lastly, if you know what sorta effect you wanna, its easier, coz you can save money on buying those you need(only thing gotta get recommendation from people or just read and read whatevers theres on internet forum. And if not sure what you need, just buy anything, coz if playing music is your own expression, any form of tool can be used, to express yourself, in the music you wanna do...
have fun