I think the quality is so much higher on the 993's vs. 996/997's. Don't get me wrong, I like the 996/997's a lot and the performance is without a doubt superior compared to the old cars. For me the 993TT is the perfect car and is easily reliable to daily drive. AMBLEZO6, get a 993TT and if you don't like it sell it for as much as you bought it for or more. I take a look at both and for me it's an easy choice:

 

After driving my 993 cabriolet for about 5 years as a DD I recently upgraded to a 2003 996tt - amazing difference and I love them both. 996tt prices are way down making for some great deals. Both are fine but the 996 is a whole new generation with all the factory upgrades. Good luck either way

 

Just for conversation...911 code names for recent years.

1989-1994 964*
1995-1998 993
1999-2004 996
2005-present 997

*964 turbo was a 965

In 1989 the 964 came later, so you still have the older 911 in 1989 as well. In some cases, the cars were introduced eariler in Europe, so you could see a 1994 993, or a 1998 996 etc.