I use titegroup, and HP38.
Had good results with both and it would be a toss up. Recently I have found myself using a lot of Titegroup in my 38 special, 45acp, 44mag, and 500 magnum. Mainly because it has been hard for me to find HP-38 or W231.
For my 45 and 38 I really like HP-38, and thought the titegroup performed better in my 44mag and 500mag.