Though I think it's important for SHIELD to establish themselves as an independant show, I think they also should take advantage of the fact that they exist in a universe with a wealth of pre established characters. Up through the mid season finale of the first season, there have technically been five cameos from the movies. So I can't be too disapointed with the number of cameos, that's one every other episode. The quality could be better though. This is how I would rank the current cameos to this point:

Episode 1-Pilot: Maria Hill. This cameo was in my opinion the best the far. It was a more extended cameo, and it involved a character who is central to the MCU. Hill was a fairly important character in the Avengers and she has mulitple picture contract. She will only become more important to the MCU. Also, it felt like it made sense that Hill would appear in this fashion. Also, unlike many of the other cameo's I felt like this one helped move the story along.

Episode 2- "0-8-4": Nick Fury. Out of everyone on this list, the most central character to the MCU. Also, Fury's character is portrayed by the most famous actor on the list, Samuel L. Jackson. The cameo was more brief than Hill's though, and it seems kind of misplaced that Fury would take the time to yell at Coulson about a plane being damaged. To me, the use of a cameo was misused. I imagine Samuel L. Jackson won't make it to the set too often, so it seems like a waste of rare opportunity. 

Episode 7 -The Hub: Jasper Sitwell. Jasper Sitwell has been in two movies with a third on the way, and also two One-Shots. Sitwell's roles in Thor and The Avengers were minor at best. His main involvement has been in the One-Shots "The Consultant" and "Item 47." This was a decent cameo, but when it comes down to it, not very impressive considering how minor of a character.

Episode 6- FZZT: Agent Blake. The characters listed above at least have a comic counterpart. Also, all of the other characters have been in a movie. Blake has been in a single One-Shot. His role was also very brief in FZZT.

Episode 3: Agent Tyler. Not even sure if this was supposed to be a cameo. The character is portrayed by "Josh Cowdery." Not really impressed by cameos if I don't recognize there even was a cameo until later.

If the cameo is going to be someone like Blake, I think you at least get him for a few episodes and give him a real reason to be involved in the story. I wouldn't think it would be hard to get someone like Titus Welliver, sure he does movies, but he also does a lot of TV, same with Maximiliano Hernandez. If your going to go through the trouble of getting a big star like Samuel L. Jackson to come by, at least make it worth the amount of time it took to get him into his costume and makeup. If the cameos are going to be 30 seconds of Agent Blake or Agent Tyler, then get them in there every episode, and dont announce it. SHIELD is good at getting my hopes up with these announcements. When they leaked that Fury would cameo, I immeadiately got my hopes up that it would be more than 1 minute of the episode.

The two best cameos were in the first two episodes. I was hoping it would only get better, no luck. In a future blog I'll talk about some cameo's I'd like to see.