Canon 40mm F2.8 $150 @ Amazon / Canon

Quote from minfordgolfer : I'm literally BRAND NEW to DSLR photography but I've researched it quite a bit. Just got a T3i 18-55 lens + 55-250 IS lI lens. What would be better the 50 1.8 for $90 or this for $150? I am looking for a good portrait lens that will blur backgrounds while keeping crisp detail on the subject, that is also good for small things in nature (bugs, rain drops,etc). The cheaper the better, but if there is a lens out there that's, say $200 that blows these 2 away than please recommend that lol!

50 f/1.8 will blur background better but it'll be much harsher background blur than 40mm at f/2.8 due to the nature of design.I won't go into all technical details, but there are various things like elements and aperture blades and stuff that have somewhat of an effect on background blur. Basically longer the focal length and small the f-stop number (i.e. smaller number means wider aperture to let more light in) will give you better background blur aka bokeh. So 200mm f/2 will give a little bit of more background blur than 135mm f/2 due to compression considering all things equal which they rarely are.

Also keep in mind that 50 f/1,8 is not very sharp (crisp detail) at f/1.8 than 40mm would be at f/2.8. Also shooting at wider apertures mean that DOF (depth of field) is very shallow and slight movement in subject or camera shake (these lenses don't have Image Stabiliazation IS which only helps with camera shake and not subject) will cause images to be not so crisp or sharp. Both are good lenses, but I'd get the 50mm since it's less money and you can always upgrade later without much loss when you sell your 50mm. If you want creamy/soft background blur, then be prepared to pay out more as lenses start getting more expensive due to exotic glass elements and more aperture blades and what not.

For shooting small things, you need a specialized macro lens with shorter minimum focusing distance (MFD) or lens with longer focal length and crop the image. Latter option is cheaper.You can also get some extension tubes, but again macro photography is very specialized and requires some degree of skill and knowledge. So you'd have to grow into it and prepare to shell out more for specialized lenses. 100mm macro is an excellent lens for both portraits and macro. One of the best bang for buck lenses IMHO.

If you are unsure, go for 50mm and upgrade later as you grow. Both 18-55mm and 55-250mm are good value for money lenses and can learn a lot from them. Never spend a fortune on lenses unless you know the limitations of your existing ones or want to do a particular style like landscape, macro, architecture, sports, portraits etc etc. Good luck shooting photos.