I will hopefully getting a Canon 350D w/ kitlens soon
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First on my list is the 50mm f/1.8
50mm is not even close to wide on a 350D - it's short tele, nice for portraits. Nevertheless, it's excellent bang for buck, and if you can spare the cash, do it.
Neither the 50, nor the 28 are very wide on the 350d if you're into landscapes, unless you want to do stitching. Have a look at something like the Sigma 10-20.
+1 I have this lens, and it's worth every penny.
Just a word of caution - that 10-20 is a Sigma DC Lens (which means it is meant for smaller sensors). If you ever intend to upgrade to a full-frame sensor
Please stop that. It's like saying, don't get the optional radio/CD with your new Citi Golf because it won't fit one day when you get a BMW. Someone just buying a 350D now is not likely to get a 5DmkII any time soon. And from what Big-Al tells me, the 10-20 does work on a full frame body, despite the DC branding.
might I recommend the 12-24 Sigma EX DG F4.5-5.6 - really nice lens and minimal distortion too (no weird fish eye barrel distortion) I bet it cost more but if you intend to put money into good glass to keep, it is probably not a bad purchase.
The 10-20 is marginally better in every respect, and has much better CA control. This is important, because you lose a lot more detail to CA on a very wide lens than on a mid-to-tele lens.
I was considering the primes because I heard you'll get a better picture from a prime lens than a zoom lens, isn't that true?
Primes traditionally have less barrel distortion and are sharper, but that's less true now with the higher-end zooms. The above mentioned Sigma 10-20 has hardly any barrel distortion - i.e. you take a picture of something square and it comes out looking square. It's pretty sharp as well - look at my photo stream, in particular
this one - there's a 100% crop of the top of one of the buildings in the picture. This picture was taken from RAW and has not been sharpened at all (I didn't know how at the time).
These days the advantage of primes are more limited to their large apertures, small size and light weight relative to zooms in the same range.