The Titan series of missiles & boosters dates back almost 50 years, starting with the little remembered Titan I ICBM. For some unknown reason, after it was deactivated as an ICBM, it wasn't used as a space booster. As was common with those first generation missiles, it had a lot of failures and had a76% success rate through 70 launches.

The Titan II ICBM was a much more successful vehicle. It was in service for about 25 years as an ICBM, served as the Gemini launch vehicle, launched the Clementine lunar probe, and ended its service launching LEO weather satellites. It had a 93.4% success rate.

The Titan III series began as essentially an upgraded Titan II with a Transtage upper stage.

Titan 3A. There were only 4 flights with 1 failure, resulting in a 75% success rate.

The Titan 3B had an Agena upper stage. All 70 of its flights were out of Vandenberg (in 1987) with 2 failures, a 97% success rate.

It was the Titan 3C that introduced the now familiar configuration of a core vehicle with two large SRBs, starting in 1965. It was developed for the Dynasoar program. It launched the first generation of military communications satellites (IDCSP), the Vela satellites, the first generation DSP launch detection satellites, DCSC-II satellites, and many others. There were 36 launches and 5 failures, resulting in an 86% success rate.

The similar Titan IIID launched large payloads into sun-synchronous orbits out of Vandenberg. Gee, I wonder what type of satellites those were? ;} All 22 flights were successful.

The Titan 3E was used to launch some large deep space payloads for NASA, the most famous being Viking I & II and Voyager I & II. Six of the 7 launches were successful, for nearly 86% success rate.

The Titan 34D was a stretched Titan IIIC type booster that was used at both Cape Canaveral and Vandenberg to launch large military payloads. It only had a 79% success rate through 19 launches.

The Titan IV was developed to launch large military payloads after the Challenger explosion. The basic Titan IV was launched 22 times with 2 failures for a 91% success rate.

The Titan IVB featured upgraded SRBs and a Centaur upper stage on some missions. Enclyclopedia Astronautica lists 15 launches with 2 failures through 2004 (87% success rate), with Cassini being the most famous mission.