I'll start with my canon prime lens.
1. Canon EF 50mm f1.4 USM
This lens have many unique attributes. Its the speediest(brightest) , sharpest and lightest lens I have. And its the only prime lens I have. I use it on many subjects and its used to be my main lens of choice . Butnow I am using more Sigma 18-50mm f2.8 EX DC for its flexibility.
I had EF 50mm f/1.8 before I bought this lens. That lens was really good value for $$ but It's lacking in USM, 5 blades diaphragm (bad bokeh), cheap plastic construction. That's why I upgraded to this f1.4 version. And I think it's a good choice.
Things I like about this lens;
- Fast f1.4 aperture allow me to shoot in any possible low light situation.
- Fast and quiet USM focusing.
- Super smooth Bokeh and depth of field
- Very light , Easy to travel with
- Super sharp. Probably the sharpest non L lens.
Things I dont like about this lens;
- minimun focusing distant could be closer
- 50mm on crop body like EOS 30D is a little long. Not suitable for tight indoor portrait, landscape etc. That hinder me from using it exclusively as a normal lens. Currently thinking of trying EF 35mm f/2.0 or EF 28mm f/1.8 USM. 35mm f/2 is very reasonable price around US$200 so i think I'll give it a try. I enjoy the fixed focal length aspect of using prime lens. It forces me to be more creative on framing and composition.
I will continue on these lenses later.
2. Sigma 18-50mm f2.8 EX DC
3. Sigma 10-20mm f4-5.6 EX DC
4. Tamron 70-300mm f4-5.6 Macro LD Di
but I already wrote quite detailed review on Canon EFS 18-55mm f3.5-5.6 Kit lens here and here.