GTA is a huge brand, its bigger than Halo.

Only thing bigger is Call of Duty and Pokemon and Mario.

last i checked halo 3 was one of the highest selling games this gen, and one of the highest selling exclusives of HD consoles.
i doubt halo 4 will outsell GTAV but it may sell more then GTAV on xbox.
one of the big issues with halo is it got worse with each new title.
halo 1 and 2 are considered the true halo games, while halo 3, reach and especially ODST and now the anniversary edition of halo CE are considered terrible

That said, as long as GTA V is good it will be fine, GTA IV was a huge let down, it seems like rockstar learned though as we seem to be heading back to san andreas ( san andreas is the best GTA, along with vice city)

Halo 3 was more liked than Halo 2 I think. Halo 3 multiplayer is still some of the best out there.

I am going to get it. Thus it is still relevant.

Yes, it's still relevant.

It has no chance whatsoever of going toe-to-toe with Call of Duty in terms of sales, though. Not a shot in Hell.

Fixed the post.  The rest was garbage.

Lol what a joke thread.

In order of relevance it probably goes (roughly):

1. Mario
2. Call of Duty
3. GTA
4. Halo
5. Gran Turismo
6. Zelda

Boring themes for GTA games has brought the series down - something more along the lines of Vice City or San Andreas is needed.

In the past GTA was vital for the industry and a gigantic phenomenon that transcended beond the gaming medium but now it's just a game among many.