Econ 1B03/1BB3 both have 3 classes a week; no writing assignments or tutorials but your midterms will be on Saturday mornings. Econ 1B03 is very easy (don't need to attend any of the classes, the prof just reads from the slides she posts online), while 1BB3 is more of a challenge (have to attend all lectures to get proper notes - unless you just watch the podcasts).
Enviro Sci 1G03 has a very small (1-2 page) writing assignment worth like 5% I believe. No tutorials for this class either, but you do have a 2hr lab every week, however depending on your TA you can usually get out within the hour.
Of course, if you enjoy math then taking Math 1B03 (Linear Algebra I) is also a good idea.
All these courses have reviews on them, just check out the review section.