if you're downtown, there's almost no bad areas. you can keep pretty central and be fine, there's hotel and hostels that are decently priced, and not sketchy as fuck. the "ghetto" downtown is pretty much hochelaga area, and i don't know much about it. keep out of montreal north, because there's nothing there. haha
all depending when you hit up montreal, there's a ton of festivals. jazzfest, comedyfest (imo meh if you don't have tickets), fireworks every saturday, osheaga in august, heavy mtl if you like metal, and other stuff.
there's a ton of cool bars, and i'd been personally meaning to check out dieu du ciel myself because they make their own beers, but along the lines of vanilla stout and all kinds of stuff.
brutopia makes their own beer as well, but it's seemed to transgressed to younger crowds, or i'm really old. they usually have live music. i think it might be happy hour all sunday, and their happy hour is until 8pm. good food but a bit overpriced.
irish embassy is generally my bar of choice, because of it's laid back atmosphere, and at this point i know the staff, and the food is pretty good and affordable. they also have happy hour all sunday long. and it's a good laid back pub kind of place. live music as well on weekends.
st elizabeth has 4$ beers on sundays. sweet terrace in the back.
if you want to pick up emo sluts, go to foufs(foufounes electriques), 4$ for ladies night, beers are like 1.25. 5$ on friday, again under 2$ beers, saturday is 8$, cheap beers, and tuesday is 5$ pitchers.
there's a cool shisha place i used to go to on st denis, called la gitane. if you want beer, tea, smoke a hookah, eat some turkish delight or pie, head there.
all around, a walk up st denis is pretty cool, there's a lot of nice buildings and ecclectic restaurants.
there's also st sulpice on st denis, that's pretty big, has a dance floor and an upstaires. giant terrace and etc.
if you're into the club scene, i don't know much, i just know my bf's friends go to tokyo all the time, and he particularly likes it because he can wear a cap and sneakers. it's also conveniently right below the ns and if3 offices. most clubs are on st laurent as well. my friends also usually go to bside or lodge or something like that.
chinatown is small, but if you're looking for sesame balls or bubble tea go for it, otherwise, it's ok.
there's also the beerfest!(mondiale la biere) sometime in june i believe. so you can get in, and buy beers and drink all day. pretty cool.
montreal, all around has a chill night scene, with lots of decoration, or just events, and people. you can pretty much walk wherever you need to go as well.
