'Classic VB' is no longer produced by Microsoft. Should you choose to use
VB, you'll need to look at VB.NET which is so different that many long-time
VB experts called it a "completely new language". It also requires the
Microsoft .NET Framework be installed on the computer.
On the other hand, Delphi is produced by Borland, who have a good reputation
for languages, but who lost their top language architect to Microsoft (he's
architecting the .NET languages, now), but have never had a great market
share. It is also based on the Pascal language, which is not currently in
high favor as are various flavors of "C".
Many would probably tell you "neither of these" (VB Classic, any version
through 6 nor Delphi) is a good star to which you should hitch your wagon.
And, since you did already know that this newsgroup is devoted to Microsoft
Access, why would you ask this particular question here in the first place?
It would only be by chance that you'd run into people here who are in a
position to compare the two languages you ask about.
Larry Linson
Microsoft Access MVP