In the past (before 360 + PSP), i never bought a system directly at launch.
When I finally bought a system, I added at least 2 or 3 games.
1983: Atari 2600 - Defender & Frogger & Pole Position
1988: C64 - Maniac Mansion & Zak McKracken & Pirates! & Pitstop 2
1992: Amiga - Indy 3 & Monkey Island & Civilization
1993: PC - Day of the Tentacle & Wing Commander 2 & Doom
1994: CD-ROM (PC) - Rebel Assault & Indy 4 (Talkie) & Wing Commander 3
1995: SNES - Donkey Kong Country 1 + 2
1996: 3DFX (PC) - Descent 2 & Tomb Raider
1997: PS1 - Crash Bandicoot & Resident Evil & Tekken 2
1998: N64 - Super Mario 64 & Banjo Kazooie & Ocarina of Time
2002: PS2 - Jak & Daxter & Metal Gear Solid 2
2003: GBA SP - A Link to the Past & Metroid Fusion & Golden Sun
2003: GameCube - Metroid Prime (bundled) & Super Mario Sunshine & Wind Waker
2005: PSP - Ridge Racer & Untold Legends & Tiger Woods
2005 (Launch-day): 360 - Kameo & Condemned & PGR3 & Perfect Dark Zero (meh) & King Kong
2006 (Launch-day): Wii - Wii Sports (bundled) & Twilight Princess & Rayman Raving Rabbids
2007: PS3 - Resistance & MotorStorm & Heavenly Sword
2008: DS lite - New Super Mario Bros. & Phantom Hourglass & Ace Attorney & Hotel Dusk & Prof. Layton
2010: iPad - Broken Sword & 1112 & Hector & Monkey Island 2 S.E. & Cogs & Osmos & Dungeon Hunter
2012 (Launch-day): PSVita - Rayman Origins & Uncharted: Golden Abyss & WipeOut 2048 & Mutant Blobs Attack & Escape Plan & MotorStorm RC & Super Stardust Delta
2012: 3DS XL - Super Mario 3D Land & New Super Mario Bros 2 & Prof. Layton 5
Wii U (probably this winter): waiting for DKC: Tropical Freeze & Super Mario 3D World & Wind Waker HD & Bayonetta 2
PS4 (probably at launch): waiting for DriveClub & Knack & inFamous: Second Son & Killzone: Shadow Fall & Watch Dogs & MGS 5
XBO (probably 2015 to catch up on some exclusives): waiting for Dead Rising 3 & Quantum Break
Oculus Rift 2 (PC): probably 2016, skipping the first model