Addy platebodies are the best, at the moment.
Top 10:
This table of high-alchemy values uses prices pulled directly from the Grand Exchange database, with the price of buying a nature rune at market price already factored in. The table will be updated automatically every day. If you see an item that will generate a profit, buy as many as you can!
1 Adamant Platebody -39
2 Air Battlestaff -49
3 Water Battlestaff -55
4 Rune Pickaxe -74
5 Lava Battlestaff -74
6 Steel Platelegs -93
7 Mithril Platebody -94
8 Rune Short Sword -94
9 Adamant Short Sword -98
10 Mithril Square Shield -98