No. 1  Grinberg-Adu (Maryland Quick Chess Ch., 2001)
The Nigerian master has the initiative on the queenside and had just played 28...d3. This measly pawn caused confusion in the white camp, and after 29.Rd2-d3, Adu cracked the whip with 29…Rxd4! The point being if after 30.Rxd4, the "zweishenzug"  e2! costs white decisive material (See this game). Adu seems to have a knack for exchange sacrifices on the d4-square (see Chess Crackers, Jan/Feb 2001, No.4).

No. 2  Weinberger-Street (Lone Pine, 1976)
This was a very interesting game that exploded into a tactical frenzy. In this position, both queens are threatened, but black does not  play 25...Bxd2 because 26.Rh1 Bf4 (26...Qxh1 27.Rxh1+ is equal) 27. Rxh5+ gxh5 with not more than a draw. While the simple 25...Qg5 wins,  the living legend reeled off the zinger, 25...Bxf3+! White eventually lost after 26.gxf3 Qh2+ 27.Ke1 Bxd2+ 28.Rxd2 Qg1+. (See this game)

No. 3  Chevannes-Kieran (United Kingdom Terafinal, 2000)
The teenage sensation from England took advantage of a weakened kingside and launched the missile, 27. Bxf5!! ignoring 27...Bc8 which apparently wins a piece. But no!!! White left her queen hanging and played 28.Rxg4! And after 28...Bxe6, white  finishes off the combination with, 29.Rh4+ Kg8 30.Bxe6+ Rf7 31.Rg4! And after 31...Qxg4 32.Bxg4, she secured decisive material and her opponent resigned shortly thereafter.  (See this game)

No. 4 Dandridge-Kreiman  (Midwest Class Ch., M/X, 1993)
Marvin Dandridge has a vivid imagination and is a tactician par excellence. Anyone who has been on the wrong end of Marvin's attack (like I have) can attest to this. Here he gives a textbook example on focal points in an attack. As one can see both f7, g6 and h7 are focal points of attack. Black's knights are overloaded and the other pieces are not in position to lend help. On the other hand, Marvin has all of his  pieces in attacking mode, so he pounced on Boris with the stunning 23. Nxh7!! (Actually…  extra points for 23.Bxg6!) This moves further undermines the g6 square, and after 23...Nxh7 (better is 23…Qd5), "Uncle Marv" throws down a second gauntlet with 24.Nxf7! undermining g6 once again. The king couldn't try to flee with 24...Kxf7 since death waits with 25.Qxg6+ and 26.Bh6#. The Calvary intervened, but after 24...Nxf7 25.Qg6+ (g6 finally falls) 25...Kf8 and it's mate in five after 26.Bh6+! Boris cried "uncle" after his move! (See this game). If you want to see another Dandridge brilliancy, see Chess Crackers, Jan/Feb 2001, No. 3.