Take a tram to the edge of St LOius on a Saturday orning and walk through to browse the frech food and vege market - buy fresh bread and cheese for a picnic lunch in the park opposite.
Take the train to Rheibfelden ( 20km upstream) and go to the thermal pool complex - includes saunas, ice and hot soak pools, theral jets f water, a salt pool etc - very cleansing, very relaxing. I like evenings best.
Take number 10 tram to Alesheim and walk up to the two castle ruins behind the village - wander in the forest. If you really enjoy walking, ealk on to catch the tram back from Muttenz of Pratteln.
Tram, then walk or bus to Mariastein. Great views.
Train to Freiburg, and to the Blackforest villages. See the worlds biggest cookoo clock and eat Black forest gateau.(day trip) Walk in the forest
Train to Shaffhaussen to see Europes biggest volume waterfall ( on the Rhine)
HIre biccled from the train station ( hey are good quality ones) and follow a bike route - any - there are hundreds of regional ones and 9 national ones. YOU can do one way by train without paying for the bike.
Also, Basel is one hour by train (approx) from Zurich, Luzerne and Bern. I especially recommend LUzerne, with its covered bridges. And take a ferry across the lake.
Monday and THursday evenings: join the Basel Dragons running club for a run. THey meet centrally under the Westeinbrukke at 1830hrs.
ANy day/evening: guided tour with a difference:
http://www.baselrunningtours.com/ ( great fun, and lots of interesting quirky info along the way)
Wednesday evenings: go dragonboating on the Rhine.
Arrange a drinke event on EF and you are sure to get to meet some of us.
If you have specific interests, let me know so I can make some alternative suggestions.