Because of trades, the Texans have not drafted in the second round in five of the 11 years in their history, but when they did make a pick, they usually nailed it. The 2nd round has been one of their most successful rounds in the draft.
As far as naming other players, there's plenty to choose from.
2011: Brooks Reed, OLB, Arizona (42); Brandon Harris, CB, Miami (Fla.) (60)
2010: Ben Tate, RB, Auburn (58)
2009: Connor Barwin, OLB, Cincinnati (46)
2006: DeMeco Ryans, LB, Alabama (33)
2003: Bennie Joppru, TE, Michigan (41)
2002: Jabar Gaffney, WR, Florida (33); Chester Pitts, T, San Diego State (50)
Out of the 8 players selected, I see only two obvious flops.. Joppru and Gaffney (who went on and had a decent NFL career as a journeyman WR), Brandon Harris is a possible third, but to say the Texans hardly ever find talent in the 2nd round isn't true.