@Tommy3103:La Candelaria (and Prado) are definitely not safer than Poblado; in fact the city centre is fine by day (pick pockets allert) but sketchy after 18.30. That's when the centre drains from the workers going home and it gets deserted. Not recommended.
Poblado is een good option if you are a first timer. Very safe, also at night. Most tourists and expats live here. Its more upscale so to say. This doesn't make for a top notch Colombian experience, but hey, you don't need worrying on safety concerns if you want to get laid right?
Another good option is Lauraless/Estadio. More Colombian, stil higher end of the spectrum as a neighborhood.
The 'Cathedral' is Catedral Basílica Metropolitana de Medellín (Cra. 56 #48-26, Medellín, Antioquia, Colombia). Once again: by day be vigilant ( a la Barcelona...pick pocket wise), after 18.30/19.00: avoid. On the west side -this is west of Av. Oriental) there are some gay hotspots. After dark use taxi's. On the east side is better. Stil use taxi's after dark in La Candelaria.
Places I liked (not for the faint hearted...):
Men's video club at Cra. 43 #56-25
La Casa Inclinada at Cra. 44 #46-38
Grindrrrrrrrr! Medellin boys are fucking models! Oh, the CB guy will be easy to meet. It's business for him, no worrie