Just a few standouts:
The Cure at the C.N.E. (Toronto) in '89 - they just played, and played, and played... each encore saw more people leave as the songs got more and more obscure... they were really playing for the die-hard fans. Not to mention the supporting acts, which were Love and Rockets, The Pixies, and Shelleyann Orphan.
Nine Inch Nails at RPM (Toronto) in 1990 - playing a fairly small club before Trent hit it big
Jane's Addiction at the Concert Hall (Toronto) in 1990
The Farm at Spectrum (Toronto) in 1991 - not the greatest band, but they put on an awesome show
Lollapalooza at C.N.E. in 1991 - Jane's Addiction, Siouxsie and the Banshees, Living Color, Nine Inch Nails, Ice-T and Body Count, Butthole Surfers, Rollins Band
Blur at Lee's Palace (Toronto) in 1991 - awesome show at a very small venue
The Who at Marine Midland Arena (Buffalo) in 1996 - playing the complete Quadrophenia with Billy Idol and Gary Glitter in supporting roles, and Zak Starkey (Ringo Starr's son) on drums - the best part was the encore when just Townshend and Daltrey came out and played Won't Get Fooled Again, Behind Blue Eyes, and Who Are You, with only Pete's guitar and Roger's stomping foot as backup, while they recalled memories of Buffalo from years earlier between songs, such as trying to revive an unconscious Keith Moon who had overdosed in the dressing room
Belle and Sebastian at Massey Hall (Toronto) in 2003
Ash with The Bravery at The Opera House (Toronto) in 2005 - not only were both bands excellent, but it was truly memorable when the bassist for The Bravery, completely wasted, got up on stage and tried to disrobe Tim Wheeler (vocalist for Ash) while in the middle of a song, and then took off all of his own clothes while still on stage!
Of Montreal at the Opera House in March of this year - simply amazing show including many costumes, props, and a very happy Kevin Barnes