In principle, a "good" system that leads to a closed game is not possible to achieve unless the opponent co-operates in achieving a closed position.
You probably already know how White can achieve an open game with the French or Caro Kann or Alekhine or simple symmetrical king pawn openings.
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. e4 e5 (1...e6 2. d4 d5 3. exd5 exd5 4. c4) (1...c6 2. d4 d5 3. exd5 cxd5 4. c4)
(1... Nf6 2. e5 Nd5 3. c4 Nb6 4. d4 d6 5. exd6 )
2. Nf3 (2... Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4) Nc6 3. d4
(2. f4!?)
So I think your best bet would be those openings which do not move a pawn in the center very early on. The only "good" openings among those (regularly played by Grandmasters) would be the Pirc or Modern Defense.
The Modern Defense does tend to be an off-beat line (good for you since that's what you're looking for). It can often transpose into the Pirc. The general principles of the Modern and the Pirc are the same - develop the Bishop on the flank and counter in the center at a later stage. If White co-operates in closing the position, which usually happens if Black plays e5 followed by White's d5, then Black can counter with the f5 break.
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. e4 g6
2. d4 Bg7
This is the basic position of the Modern Defense. As you can see, this position can be reached even after 1. d4, so it's very flexible.
There are many different ways for White to continue in this position. Black's usual idea is to play d6 followed by a later e5, although there are games where Black has tried to break white's center with c6 and d5 or even c5.
Here, I give some sample lines which may lead to closed positions, including all three ideas of c5, d5 and e5. Note that even in these lines, White has the option to open the position, but it doesn't necessarily give White an advantage in doing so. In fact in many lines, White prefers to close the position to cramp Black for space.
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. e4 g6 2. d4 Bg7 3. Nc3 (3. Nf3 d6 4. Bc4 Nf6 5. Qe2 O-O 6. O-O c6 7. Bb3 Bg4
8. Nbd2 e5) (3. c4 d6 (3... c5 4. d5 d6 5. Nc3 Nf6 6. Nf3 O-O 7. Be2 Bg4 8. O-O
Nbd7 9. h3 Bxf3 10. Bxf3 a6) 4. Nc3 Nc6 5. Be3 e5 6. d5 Nce7) 3... d6 (3... c6
4. Nf3 d5 5. e5 Bg4 6. Bf4 Qb6) 4. Nf3 (4. f4 Nf6 5. Nf3 O-O 6. Bd3 Na6 7. O-O
c5 8. d5) (4. Be3 Nf6 5. Qd2 c6 6. f3 b5 7. g4 h5 8. g5 Nfd7 9. f4 Nb6 10. Nf3
O-O) 4... c6 5. Be2 Nf6 6. O-O O-O 7. a4 Nbd7 8. h3 Qc7 9. Be3 b6 10. Qd2 Bb7
11. Bh6 a6 12. Bxg7 Kxg7 13. Qe3 e5 *