If I was to return to 1.d4 I think I'd be tempted to play something like 7.Bb5+

i.e:

1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Bb5+!?

The games in my database look rather congenial for white, in my opinion.

Or have the recent books on the GI come up with something good for black?

1.Nf3 d5! 2.d4!!--a dirty trick

  If you know your opponent plays the Grunfeld, I agree with the delay of d4.  Combined with g3 it is very hard to get the typical Grunfeld counterplay.  I have a devil of a time vs the English type positions when I play the Grunfeld.

  In the book "Opening for White according to Kramnik Vol 1" the line 1.Nf3 Nf6 2.c4 g6 3.Nc3 d5 4.Qa4 is given as one of the options.  I think that Kramink's entire opening repertoire with 1.Nf3 is rather good.  He limits what Black can play and avoids some "Daring Defences".

I've been a grunfeld player for almost 3 years but recently I've stop playing it because some lines didn't apeal to me.
More exactly, there is some lines in which black have significant difficulties for playing for a win.
If you want a relatively safe line in which black has few chances to win, i recommend 1.d4 Cf6 2.c4 g6 3.Cc3 d5 4.Cf3 Fg7 5.Ff4 0-0 6.Tc1 dxc4 ( there is other option but i don't believe in it) 7.e3! (7.e4 Fg4 or 7...b5!? gives black plenty of play) 7...Fe6 (maybe 7...c5!? is the way where black should look at) 8.Cg5! Fd5 9.e4 h6 10.exd5 hxg5 11.Fxg5 Cxd5 12.Fxc4 Cb6 13.Fb3 Cc6 14.Ce2 and, in my opinion, only white could manage to win such a position.

I can heartily recommend the line with 4.Bf4, 5.e3 and 6.Rc1 (keeping the king's knight at home for the time being).  The princiapl point is that if Black plays 4.Bf4 Bg7 5.e3 0-0 6.Rc1 c5!? 7.dxc5, many Grunfeld players will semi-automatically play 7...Qa5, which is a normal tactic in this type of position.  However, in this specific position, because the Rc1 bolsters c3 and the Ng1 can still come to e2 to provide further support, White can play 8.cxd5! with (in my view) a clear advantage - Black has real trouble regaining the pawn or generating sufficient pressure to compensate.
Of course, Black does not have to play this: 7...Be6! is a good try, although most sources seem to think White can emerge with a slight plus, and it is certainly not necessarily the sort of position a Grunfeld player will relish playing.
Even better probably is to avoid 6...c5 and play 6...dxc4 whn 7.e4 b5! is very sharp and interesting - so maybe not what you are looking for - but then as others have said there is no way to avoid complications entirely if you are going to try for a significant advantage (not just in the Grunfeld, either, but in any opening).

Hans Berliner did propose the improvement 13. Rc3 Qd6 14. h4 h5 (practically forced) 15. f3 and tried to prove that White was much better, however the analysis has now essentially been shown to lead to no advantage for White in a couple of NIC columns in the forum section. One move that is not mentioned in any sources I have seen that seems to present problems though is 15. ... e6 blockading the kingisde whilst providing the straightforward threat of Rd8 when Whites d-pawn will drop, in the long term White's position just looks ropey with no real co-ordination.

  As a life long Grunfeld player, I will share some of my pet peeves.  I play the Grunfeld to get unbalanced positions.  If you don't like them, why play the Grunfeld?

  If it matches your style, one of the less exciting variations such as Bf4 or a g3 variation are annoying to a Grunfeld player.  If you want a full-blooded fight then the Exchange is the way to go.  I reccomend reading through Rowson's book on understanding the Grunfeld and choosing a line you like.

  My experience is that I am about the only Grunfeld player when I was in Texas and the same in New Jersey.  You could spend a lot of time on something with little payout.  This is one of the reasons I play it as so few others do.

There really is no "safe" line in the Grunfeld that will give White an advantage.

I am a "Former" 1.d4 player, and against the Grunfeld, I've always found the following line to work best, but if Black knows the line, he can get equality out of it (though White's king is "FAIRLY" safe).

1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 (Or Black can play 6...c5.  In this line, basically Black's moves 6-9 involve ...c5, ...Nc6, ...Bg7, and ...0-0, though order really isn't important here) 7.Bc4 c5 8.Ne2 Nc6 9.Be3 0-0 10.Rc1 cxd4 11.cxd4 Qa5+ 12.Kf1 and now 12...Qa3! Gives Black full equality as White can't play f3 due to the loose bishop on e3 then.  Therefore ...Bg4 is a threat.  In response, White should play 13.Qb3, when Black has the choice between the rare 13...Qd6, or the most common, 13...Qxb3.  Play is equal, but the Queens are gone, and the attack is therefore reduced.

Now many players aren't familiar with the line, and don't play 12...Qa3.  Against moves like say, 12...Bd7, White starts using the h-file for an attack.  13.h4! intending h5 and hxg6.  This is not a very good plan if the Queens are gone, but otherwise, this attack can often be lethal for Black.  I actually just started taking up the Grunfeld again as Black, and I can tell you that against me, you'd get 12...Qa3, since I obviously know the correct line of play for Black.

But as your other responder said, the Grunfeld is dynamic.  You can't play a "Safe" line against the Grunfeld and expect any advantage.

I am seeking everyone's advice here.  Does anyone have a good, solid, safe line FOR WHITE against the Grunfeld ?   I mean a line that gives a slight to medium plus without much risk and where white does not have to sacrifice a pawn.  For example, what would you play as White if Kasparov played the Grunfeld Defense against you ?

Perhaps, a person who plays the GRunfeld regularly might have some interesting ideas here ?

Help....