Why do you prefer one or the other? What do you do to make your adventures memorable?
I personally can't stand running canned adventures though I do enjoy playing in one from time to time. "My current campaign":http://www.obsidianportal.com/campaigns/star-trek-late-night is a massive sandbox. The players make thier own destiny and choose the path they will take. I have a preset timeline that I use to have events ongoing in the background. The players actions may intersect with the timeline or may run paralel to it. I also utilize a game changing "drama deck":http://bit.ly/uL5Jor that allows the players to act like a producer for the movie and make changed to the script. These cards can have a major and unexpected inpact on a scene. This requires me to react and adjust quickly on the fly. I never know what to expect from the players from week to week so the adventures are often just as new to me as they are to the players. I know this style of play is chaotic, and requires alot of work on my part, but I love it and it is the style of play my team is use to.
"Star Trek Late Night":http://www.obsidianportal.com/campaigns/star-trek-late-night
"Duskreign's CotM December 2011":http://www.obsidianportal.com/campaign/wyrmshadow/wikis/122011
"CotM January 2012":http://blog.obsidianportal.com/star-trek-late-night-januarys-cotm/?utm_source=rss&utm_medium=rss&utm_campaign=star-trek-late-night-januarys-cotm