Hi Joe - it is difficult to to find cashflow positive buildings on the north side unless you provide a substantial downpayment - often times to make it work, you almost need to be owner occupied to avoid a greater than 20% downpayment and more attractive interest rate. I work a great deal with investors - large multi-units. Currently I have had a great deal of luck finding a number of 3 to 6 flats in South Shore that in terms of cashflow are very attractive. Easy access to Metra along S. Exchange makes it convenient for tenants. The key to evaluating any investment property is to think of a three-legged stool - cashflow / cash on cash return, appreciation and tax benefits (ie depreciation). Many of these buildings have significantly better returns than buildings on the north side.
South Shore area is 6700 South to 8900 South - Stoney Island east to the lakefront. The area has seen steady appreciation - a very large development is planned at 89th and the lakefront - empty land along the shipping channel.
I've read that Pilsen is the new Bucktown - after doing a fair amount of analysis of the buildings available, I am not convinced the current prices are worth the price - simply my opinion.
Hope that helps!