If you have Zeitgeist daemon running on your system, it should save some helpful info to ~/.local/share/recently-used.xbel file. Zeitgeist monitors access to files on disk, so it should know your most recently played video file. Unfortunately the files are not sorted by file access, but the database contains that information too, so you can grep all data you need and then look for most recently file in a loop.
I just wrote a Bash script to find the most recently played file with "video/*" MIME type and play it using SMPlayer (but you can use any video player, of course).
# get list of files with MIME type "video/*"
video_files_list=$(grep -B3 "<mime:mime-type type=\"video/" ~/.local/share/recently-used.xbel | grep "modified=")
while read -r line
# extract modification time (last access to file)
date_line=$(echo "$line" | cut -d'"' -f6)
if [ "$date_recent" \< "$date_line" ]
file_name=$(echo "$line" | cut -d'"' -f2)
done <<< "$video_files_list"
# file name is encoded like URL, use Python to decode it
file_name=$(python -c "import sys, urllib as ul; print ul.unquote_plus(\"$file_name\")")
# play video
Save it to file, add permission to execute and it should work.