This is where all the afterhours clubs are (and in general a greater diversity of clientele). That perhaps is the only unique draw to downtown. Though there are lots of other, more main-stream, night spots downtown, their popularity and concentration nowhere near matches Whyte Avenue or West Edmonton Mall.
To give you a sense of diversity of places, here's my attempt at an exhaustive listing of the night spots (excluding bars in hotels) in downtown, from east to west:
-Donna's (lounge, Canada Place 100 St - 101A Ave)
-Sherlock Holmes (pub, 100A St - 101A Ave)
-Four Rooms (restaurant with live music, Edmonton City Centre East, 100A St - 102 Ave)
-New City Likwid Lounge (dance club, 101 St - Jasper Ave)
-Baccarat (casino, 101 St - 104 Ave)
-Y (afterhours club, 102 St - 100 Ave)
-Crystal (R&B/Hip Hop, 104 St - Jasper Ave)
-Sublime (afterhours club, 104 St - 102 Ave)
-Mezza Luna (Latin club, 104 St - 102 Ave)
-Fly Bar (lounge, 104 St - 103 Ave)
-Roost (gay club, 104 St - 104 Ave)
-Chez Pierre (strip club, 105 St - 100 Ave)
-Climaxx (afterhours club, 105 St - 100 Ave)
-Halo (dance club, 105 St - Jasper Ave)
-Metro Billiard Cafe (pool hall, 106 St - 103 Ave)
-Boots and Saddles (gay bar, 106 St - 102 Ave)
-Secrets (lesbian bar, 107 St - 103 Ave)
-Caliente (Latin club, 108 St - Jasper Ave)
-Martini (lounge, 109 St - 100 Ave)
-Globe (bar/club, 109 St - Jasper Ave)
-Ceili's (Celtic pub, 109 St - 104 Ave)
-Overtime (sports bar, 110 St - 103 Ave)
-Stonehouse (pub/bar, 111 St - Jasper Ave)
-Majestic (dance club, 112 St - Jasper Ave)
-Sidetrack Cafe (bar/restaurant famous for its live music, 112 St - 104 Ave)
More choices and variety, though sparser, as you head west into Oliver and then north on 124 St.
Dress Code: Definitely depends on where you go, but again, dress code is usully pretty lax (except for the Latin clubs).
The Roost Niteclub, Buddy's Niteclub, Woody's Niteclub, The Precinct, Boots & Saddles, Fly Bar, Secrets, Gay Denny's.
These are all gay/lesbian/bisexual/transgendered nightclubs. All very fun (if you're into that). A lot of straight women attend these clubs as well as a safe haven from creepy guys trying to hit on you. For younger cute boys (18-25) watch out for the old men, some of them are creeps. The precinct is primarily for lesbians. Boots & Saddles is primarily for the older crowd. The Gay Denny's is where everyone goes after the bar. Typically Buddy's and Woody's is popular on Friday nights and the Roost on Saturday and Sunday nights.
Dress Code: Most are casual dress except for Woody's and Fly bar which is business dress.