What I have:

Fenders (if riding in rain)

Dinotte 140L tail and 200L head light, though the SuperFlash is totally acceptable most of the time. I just like the extra safety of the 140L because I ride even in heavy rain and heavy fog. 99% of the time the superflash would be fine. I dunno about front lights for < $100 - I never found anything I liked but others will help here. It depends on whether you need it to see or to be seen.

Rack & pannier - but whatever you have to carry your stuff in is fine.

Tools:
cheap $10 multitool from a department store is all I really use. A couple of wrenches besides that if you are going to be changing pedals, etc, but you don't need to carry those on rides.

Spare tube

Topeak Road Morph pump

Tire levers

glueless patch kit in case you flat more than once before getting home

"real" glue patches to fix the tube *properly* when you get home - I buy the $2.49 patch kit from Harbor Freight which has many patches in it:
http://www.harborfreight.com/cpi/cta...emnumber=97204