does logic 8 have good mixing plug-ins, like delay and reverb?
Yes, they are very good IMO. Look in the manual, in particular for space designer and delay designer.
Or should I buy that waves bundle?
Which waves bundle? There are a lot of of them costing from a few
hundred to many
thousands of whatever your local currency is.
Hopefully the mixing plug-ins that come with logic are good but what do you all think?
I assume from this and other posts that you are starting out with logic. If that is indeed the case, I would suggest that you gather plenty of experience with Logic's own effects. Trust me, if your mixes don't sound good, it will not be because the logic plugins aren't up to scratch
kind regards
Mark